Preventing Heat Stress in the Workplace with Tom Bernard

Heat stress is no joke.  Exposure to excessive heat and
working in hot environments can cause Heat Exhaustion, Heat
Cramps, and even Heat Stroke. The stress that heat puts on the
body can be deadly if not identified and addressed. 


On this episode, Thomas Bernard, PhD, CIH, CSP, and PE talks
about heat stress, its effect on the body and how to prevent
it.  Tom is a professor at the University of South Florida,
College of Public Health and director of the Sunshine ERC a NIOSH
Education and Research Center.  He has done extensive work
studying the components of heat stress and has helped develop
heat stress management programs for a variety of occupations.


 


Pete Koch: [00:00:03] Hello, listeners, and
welcome to the MEMIC Safety Experts podcast, I'm your host, Peter
Koch. Heat stress is no joke. Exposure to excessive heat and
working in hot environments can cause heat exhaustion, heat
cramps and even heat stroke. The stress that he puts on the body
can be deadly if not identified and addressed. And even in its
early stages, heat stress can deteriorate mental and physical
performance to the point where minor hazards can become major
exposures. Personal factors can also complicate the prevention of
heat related emergencies. So a better understanding of how heat
affects the body and how to gauge how hot is too hot are key. So
on the podcast today with me is Thomas Bernard, Ph.D. in C.I.H.
and Tom is a professor at the University of South Florida College
of Public Health and the director of the Sunshine ERC, a NIOSH
Education and research center. Some of Tom's other [00:01:00]
certifications and qualifications are a Fulbright scholar from
the Lambroso University in the United Kingdom. He's certified in
public health. He's a certified safety professional, a certified
industrial hygienist, a certified professional ergonomist, and a
registered professional engineer. Tom's interests in heat stress
include how clothing affects heat retention and dispersion,
physiological monitoring, personal cooling methods and exposure
assessment. He has done extensive work studying the components of
heat stress and has developed heat stress management programs for
a variety of occupations. Tom, welcome to the podcast.


Thomas Bernard: [00:01:37] Peter it's great to
be here and I'm looking forward to talking to you about heat
stress and maybe just a tad bit of cold stress as well.


Pete Koch: [00:01:45] That's fantastic. And, you
know, as we were talking before the podcast, the heat stress
piece really was supposed to be the main focus. But I threw a
couple of questions in there at the end about cold. My background
is really in the ski industry. But as we talked about before,
there are some [00:02:00] heat related challenges, even in colder
occupations. And cold has its own set of unique challenges that I
hope we get to touch on just a little bit. So maybe at the end.
So as we start to flow through here, why don't you tell me a
little bit about how you got interested in heat stress and came
to understand that it needed more further study?


Thomas Bernard: [00:02:19] It can be, and in
some regards, a long story. So it goes back to the fact that the
early 70s, I was working at a department at the University of
Pittsburgh Graduate School of Public Health, and this lab was
famous for their heat stress work. And while I was studying
metabolic demands of coal miners, I was in this department and
actually participated in a couple of experiments that were going
on at that time. So I think my introduction to heat stress was
back when I was a graduate student. It continued at my time at
Westinghouse, [00:03:00] where I was primarily interested in heat
stress in nuclear power plants. And in fact, we developed some
guidelines for the power industry that started with the nuclear
field, but was eventually distributed out to all the electric
power industry. I ended my move to the University of South
Florida. That became a major interest in terms of a research
agenda and that's been going on for more than 30 years. And I
still remain fascinated by it.


Pete Koch: [00:03:38] It really is a fascinating
piece, just the effect. I mean, we're warm blooded creatures, so
you wouldn't imagine that living in heat or working in heat would
have such an effect on us. But it really does. And I think
everyone listening can relate to being too hot at one point in
time in their lives or maybe multiple times. So I think it's a
good [00:04:00] time to talk a little bit about what the effects
of heat stress are on the body. What does it do to us and what
are some of the things that we might feel when we start getting
too hot?


Thomas Bernard: [00:04:10] And you know, you're
right. So the first thing I want to point out is that, yes, this
has been the experience of almost all of us. My caution to the
health and safety people are because it's such a common
experience that we often don't appreciate all of the risks. If
you allow me a very bad analogy, it's like driving. We all drive.
We all thoroughly under appreciate the risks that we undertake
every time we drive. So in terms of response, we're warm blooded.
That is true. But the other is we're fundamentally tropical
animals so that we evolved in a way that we're accustomed to
dealing with heat and we have natural physiological [00:05:00]
responses. So the first of those is as we need to dissipate heat
from the body. And by the way, heat stress is a problem of taking
that internally generated heat and dissipating it out to the
outside environment. So when we work, we generate heat that has
to be dissipated out. The very first thing that happens is we
increase our blood flow to the skin. So it's a cardiovascular
demand and a cardiovascular response. Once it reaches the skin,
then the most important way we have of dissipating that heat is
then by sweat evaporation. So the second response is that
evaporation of sweat or sweating and the evaporation of sweat and
the other responses that's very kind of been there is that we do
have an increase in our body core temperature as [00:06:00] well
as an increase in our skin temperature. So the basic responses,
our cardiovascular body temperatures and the sweating.


Pete Koch: [00:06:11] So when those and those
are all normal responses to us getting too warm and that that in
itself is heat stress or getting warm, I guess. And then we go
beyond our and our body starts to not be able to dissipate heat
enough. And we get into some really negative effects then of heat
stress, correct?


Thomas Bernard: [00:06:32] Yes, that's correct.
And I may drift into this and later in our podcast. So I want to
make a differentiation. So stress will be those things that are
external to the body that are causing the physiological
responses. And then heat strain represents those physiological
responses. So like stress strain relationships and in other areas
of science. So the stress [00:07:00] comes from the work demands
and the environment. The strain is our response back to this and
that strain becomes excessive. Then it's manifested in the heat
related disorders and these can be seen in the excessive demands
on the cardiovascular system and will usually then classify those
illnesses as heat exhaustion. So a cardiovascular insufficiency
and heat exhaustion can go hand in hand. The other is that if the
temperatures get high enough that we actually affect the central
nervous system. So we affect the brain and the way the brain
helps control our responses to heat stress. And then those will
be heat stroke so that when we have a CNS dysfunction, central
nervous system [00:08:00] dysfunction, then we have heat stroke.
Heat exhaustion is serious heat stroke as a medical emergency.


Pete Koch: [00:08:10] That's a really good
differentiation there. And we're going to get in towards the end
of the podcast about the responses to those, because those are a
really it's a really key thing to understand, and especially when
you get to that central nervous system shut down almost in the
later stages of heat stroke or of that heat strain that you have
to recognize it right away. And a lot of people don't. One of the
things that I love to do is to actually coach. I coached high
school girls soccer. We start our preseason early on, later in
the summer, so early August, end of July. And we have some really
hot days. And if you don't pay attention to how the girls are
functioning during that practice, they can easily go into
[00:09:00] a heat emergency. And you need to be prepared to
manage that if you don't see the cues early on. And we'll talk
more about that later on. But it's near and dear to my heart when
we start talking about the responses to that. And so let's talk a
little bit more about how, as you get into our bodies, inability
to manage the stresses that are there, how does that affect the
person from and we're talking about workplace safety. So how does
that affect the person's ability to perform in the workplace?


Thomas Bernard: [00:09:36] Ok, and I appreciate
your example of soccer, so let me deviate for a moment and the
fact that you started in early August and I presume that you step
up your practices, you don't go for it right away. And we do this
in order to allow our athletes and in your example and workers
[00:10:00] and mine to adapt physiologically to heat exposure. So
what we have is a process of acclimatization, and it does a
couple of things. One is that there's an earlier onset to
sweating, and that's important because then we get cooling going
earlier. The other is that we have water and salt management
physiologically. And so acclimatization helps manage and retain
electrolytes and so that the sweat becomes more and more diluted
so that it becomes almost water. And that's important. OK, so
another physiological adaptation as we get exposed. What we find
is that at the very early step ups is that we are actually making
the transition for something that's thermally [00:11:00]
comfortable up to where we reach what would be ordinarily an
occupational exposure limit. We're already beginning to see an
increase in unsafe behaviors. And in fact, there's some classic
studies that go back and show that from a neutral environment
where unsafe behaviors are minimum, not zero, to where we get to
the widely accepted occupational exposure limits, we already see
more than a 50 percent increase in unsafe behaviors. And
following from the unsafe behaviors are accidents. And with
accidents, we have injuries and resulting losses to the
environment or our equipment. So this becomes important and it
continues to go up as the heat gets higher. Then with that, we
get starting to get a decrease in work performance [00:12:00]
because we're taking some of that cardiovascular capacity that we
would ordinarily use to support work. And now we're shunting that
blood off to the skin in order to be able to cool ourselves. So
it's clear that productivity will decrease with increasing levels
of heat stress. And that has all to do with how the body's
allocating blood.


Pete Koch: [00:12:27] Since how the body
allocates blood and how it responds to the environment in their
own. Your own internal temperature is going to be different with
every person. I imagine that heat stress will affect people
differently. So it's not going to be it's not going to be a
consistent response across the board like you would have with
another exposure that might not be environmental, like fall
protection or exposure to like a spinning machinery or something
to that effect.


Thomas Bernard: [00:12:56] Yes, so heat stress
has a lot to [00:13:00] interindividual variability, so there's
some people who, first of all, there's a small group of people or
just heat intolerant, but let's set them aside for a while. Even
in the range of heat tolerant, you're going to see a huge
variation. Some people can deal with heat stress in incredible
ways, and other people are going to be somewhat less tolerant,
not importantly less tolerant. And we set our guidelines to
protect those people with less tolerance. So not the intolerant,
but people with less tolerance. And then that means those people
with a with a high level of tolerance. Wonder why it is that we
are saying that you're in a heat stress situation. And, you know,
it's not only the difference between people, but even [00:14:00]
within the same person, the day to day variations can be quite
substantial. So you may be less tolerant one day and more
tolerant the next. And we really don't know why that is, but
probably has to do with recovery and just how our days vary a
little bit.


Pete Koch: [00:14:20] I can definitely see that
with the athletes that I work with and because I can work with
them every single day. And as a safety professional, I don't
always get to work with the same group of people every day.
Sometimes I do, but it's typically in a workshop or a training
standpoint, and you're not going to have the same kind of
physical demands that you would as an athlete on the field or a
worker in a hot environment or highly physical environment that
they might have that same challenge. So I can definitely see that
in the athletes, you're going to have a group of people that are
really, they're very tolerant to heat. They can manage it all the
way through. And we do step our [00:15:00] practice sessions up.
We start very slow and then we work our way up as we go through
the summer. We step it up within the practice as well. So there's
definitely a warm up period, a cool down period. And we don't
just jump right into a lot of heavy physical activity so that we
can work the athletes into that process or into getting warm and
then getting their body used to be able to dissipate that heat as
they go. What I've found with the athletes from the difference
from day to day is there is a sort of an unknown component like
you'd say, I just like I don't know why yesterday you were very
tolerant to the same temperatures and today it's actually a
couple of degrees cooler. The humidity is a little bit less and
you are not responding in the same manner. Those are the
outliers. I think consistently, though, what I've seen,
especially with the younger athletes, [00:16:00] is their food
management and their hydration management is relatively poor in
that, you know, they might be drinking in practice. But what we
typically tell them is that it's what you drank yesterday. It's
going to help you hydrate for the practice today. And I think
that's a key part. So in your studies, how does water management
help someone deal with heat stress?


Thomas Bernard: [00:16:29] Yeah, water
management is incredible stuff. But and I want to caution your
listeners at the same time. It's not the answer to all your
problems. So this is one thing I like to point out. So on a job
where there's a lot of profuse sweating, we recommend that you
plan to have one quart of water per hour per person, and then
that tends to be on the high end of [00:17:00] what the what will
actually be drunk, but assures that you'll have sufficient water
or other drinks available. But it's important to know that you
probably cannot replace more than about six quarts of water and a
working shift be at eight or 10, 12 hours. You're almost always
going to have a deficit of water by the end of the day. And then
what we really rely on is that you get that hydration completed
during the off hour. So let's just assume it's a day shift, you
know, in the evening and in toward the night that the water gets
replaced. So you show up to work the next day. We always assume
well rested, fully recovered and hydrate. That's what we pray for
when they show up for work the next morning,


Pete Koch: [00:18:00] And [00:18:00] that always
happens. I mean, that's consistent, right? Everyone shows up well
hydrated, well rested and prepared for the day. But that is an
interesting part. I think education and again, getting into this,
we'll get into it later as we talk about response and training.
But education about, you know, if you're working in a hot
environment, if you want to be prepared for that environment for
the next day, what you do in the off hours really does affect you
will affect your performance and response during the on hours as
well. And it won't just help you at work. It will help you in the
softball game after work or in the fishing expedition that you
have over the weekend and any of that. So water management,
education around that I think is good and great caution out
there. It's not it's not the panacea. It will not be the solution
for all the problems. And again, something that we'll talk about
a little bit later on


Thomas Bernard: [00:18:54] One thought I left
hanging there. You have to be well hydrated [00:19:00] in order
to be as tolerant as you're going to be of heat. So hydration
doesn't give you any sort of superpower. It allows you to be
yourself when you're dehydrated, you detuned yourself. And so we
have to be careful that that water is permissive. But it's not an
intervention that will make things better. We only want them to
be hydrated.


Pete Koch: [00:19:29] Excellent point. I like
that water. Water is not a superpower. Perfect people. Yeah. And
you hear it all the time. Drink water, drink water, drink water.
Like it's going to make you better. It's only going to allow you
to be yourself that sorry to repeat your words, but I think
that's important for our listeners to take with them. And that's
a really important point. Let's talk a little bit about now how
you might measure heat stress and, you know, we all we all have
that feeling of it's hot. Well, like, [00:20:00] how do we know
what hot is? How do you measure hot? So in in my preparation for
this podcast, the term Wet Bulb Globe Temperature came up in a
lot of the research that I saw. And I have some understanding of
that just from my years making snow because we used the wet bulb
temperature to determine humidity and whether or not we could
make snow actually above 32 degrees, which you can believe it or
not. So how does Wet Bulb Globe Temperature? How does that get
used in measuring heat stress? And how does it differ maybe from
ambient temperature?


Thomas Bernard: [00:20:37] Ok, so let me try
that in a couple of different ways. So first of all, remember, I
mentioned that the primary way that we lose heat is by sweat
evaporation. And so that means that we have to have that. Pardon
me for a technical term for a moment, but we have to have a
gradient that drives that's sweat [00:21:00] evaporation. So I've
got saturated water vapor on my skin and that drives to the
environment. Getting away from the technical point then for a
moment is that the drier the air, the more rapid that sweat
evaporation is going to be in, the greater cooling I get. And
then, of course, is the air becomes more humid. That ability to
move water off the skin and into the air gets lower and lower.
And by the time I reach one hundred percent relative humidity, I
can no longer get sweat evaporation. And that really limit starts
in and around 70 percent or so you start to see a diminishing
return. So that is humidity is really the critical issue and not
the air temperature. So when we talk [00:22:00] about the how hot
it is in terms of the air and even to the extent that we talk
about radiant heat, those are relatively small thermal loads on
the body when we in comparison to the metabolic demands.


Thomas Bernard: [00:22:16] So remember, I
mentioned earlier, heat stress is a problem, getting internally
generated heat out to the environment and the heat would be alone
on the body from higher temperatures and radiant heat is probably
no more than 10 percent of the metabolic rate. So it's not a big
piece of it. And said the other way, sweat evaporation is that at
least 90 percent of the heat loss there. So when we talk about
assessing the environment, it turns out that we really want to
wait that humidity. So the wet bulb temperature, the dew point
are good [00:23:00] way. So when you listen to the weather
station and they report, you know, they'll report dew point.
Don't think about relative humidity, think about dew point. And
once you start getting dew points that are up over 60, say,
sixty-five degrees Fahrenheit, you're starting to report that
it's humid. And by the time you're up to 70, you're clearly in a
very humid environment. And so when people say it's hot, they may
report dry, they may be reporting dry bulb temperature, but
they're probably really reporting this kind of synthesized
humidity and temperature.


Thomas Bernard: [00:23:39] And if they're saying
that it's hotter occupationally, it probably already is. All
right. So that guidelines not too bad. And in fact, that might be
that even though you're standing there, it feels a little bit
comfortable. But when you begin to work and have to dissipate
that extra heat, it's actually [00:24:00] going to be important.
So WBGT getting back to actually your question is that that's wet
bulb globe temperature. So wet bulb we now we've established is,
is what is going to be sensitive to the level of humidity and the
and the globe temperature is really a combination of the air
temperature and radiant heat in the environment. So if you will,
the wet bulb temperature represents our ability to dissipate heat
to the environment and the globe. Temperature takes care of the
convective and radiant heat load that we may have. And the WBGT
is highly weighted to the wet bulb temperature so at 70 percent
of the wet bulb temperature and 30 percent of the globe, and I
like the WBGT [00:25:00] because it really represents in a very
simple index, the ability of the body to dissipate heat to the
environment and back our physiological responses will map to WBGT
pretty well.


Pete Koch: [00:25:16] So then as we as we start
to look at the workplace, how do you measure that in the
workplace? Typically you see thermometers in the workplace or you
might get someone with a weather report in the workplace. I know
that we had when we were working at the ski area to look at the
wet bulb temperature, to determine humidity in the air and making
snow on the other end. So the cold part of that, we had
thermometers and different devices that would do that. But it
wasn't something that you just ran out to the hardware store and
grabbed. So what do you use to measure that?


Thomas Bernard: [00:25:47] Yeah, well, in a
minute, I'll tell you, how to go to the hardware store to get
this stuff. But more likely, you need to have a high [00:26:00]
quality instrument that will measure WBGT and there is a lot of
cheaper things that pretend to measure this. So, so cheap is not
going to be an answer. I'll provide you that answer in a moment.
From a credible vendor a WBGT instrument is the usual way that a
health and safety person will measure that in the environment.
Globe temperature. Though, historically, is that somebody in the
nineteen thirties, I think it was, went to the hardware store,
got a toilet bowl float that happened to be a six inch copper
globe copper sphere, put a thermometer into the middle of it and
that became globe temperature. So, yes, you can go you're not
going to go [00:27:00] to a hardware store anymore because
they're plastic in the ellipsoid. But you can order online a
fairly cheap six inch copper globe and make your own globe
temperature. And in the same way, wet bulb temperature is you get
a regular thermometer, you put a wick that can be something like
a white shoelace that is then immersed in water and then allowed
to freely evaporate to the air. So you can build, if you will,
your own homemade WBGT device. That will be very good. And the
thermometers have to be a good quality, but there are some not
good thermometers that are readily available.


Pete Koch: [00:27:51] I think you've just given
me a new science project for our homeschooling group, so I think
we might be doing that in a couple of weeks. See how that goes.
I'll get back to you [00:28:00] if I need a list of supplies. So
considering that, you know, so the best way then for an employer
to measure heat stress in the workplace is WBGT. And I think
you've described why, because it does represent the workers
ability to maintain their thermal equilibrium. What other factors
contribute to heat stress in the workplace and how do they affect
it?


Thomas Bernard: [00:28:28] So we talked about
the environment and WBGT is a good measure of the environment and
especially because we are concerned about the humidity. Obviously
it once I say it out loud yet again, is the metabolic rate, the
work demands.is the second job risk factor, because what's going
to happen is whatever limiting WBGT there is, you're going to
have to make it cooler and drier, [00:29:00] if you will, with
the higher metabolic rate. So it's not going to be one value
WBGT, but rather a relationship between the environment and the
internal heat generation so that you can maintain thermal
equilibrium. So the environment has to be more conducive to the
sweat evaporation the harder you work and then. We have to worry
about what they're wearing. So the third job risk factor is the
clothing. Not most of all, occupational exposure limits are going
to assume work clothes, so that would be something like a six
ounce woven material, long sleeve shirt and eight ounce woven
material pants. It could be coveralls as well as woven material
that. But that's [00:30:00] the base unit. If you're in shorts.
Or a T-shirt, you can afford to be a little bit higher than if
you're in a double layer, coveralls are in the worst case,
barrier clothing. Then we have to really change that threshold
WBGT to match.


Pete Koch: [00:30:24] It sounds as we start to
look at the workplace itself and we have the humidity and the
temperature and the WBGT in the environments, and then we have
the work rate in the environments, it's compounded really not
just by what they wear to work, but what they're required to wear
for work, possibly personal protective equipment and things of
that nature. So that's even going to be a contributor. And if you
can't remove one of those, then it really comes back down to
trying to mitigate the environment [00:31:00] or mitigate
exposure. So maybe the amount of work time or time in the
environment.


Thomas Bernard: [00:31:07] Yes, that's correct.
So and let me just go off on a tangent for a moment. It's almost
always going to be the clothing that's going to be the big
factor, a full face, negative pressure respirator, which is about
the worst that you can imagine, really doesn't affect heat
stress. You'll be very uncomfortable. But it won't affect your
level of heat stress. The same can be said about gloves and
shoes. That's where the major part of the body surface is
covered. That's the question of what the PPE effect will be. And
I totally lost track in your question.


Pete Koch: [00:31:51] That's OK. I think just
thinking more about the PPE itself, and I think that's a good
point. And it's not going to be one particular piece [00:32:00]
of PPE, but it's going to be the combined effect. And how much of
the body is covered by clothing and PPE? Because, again, if
you're if you're in a full-face respirator, but you are in a
position where you can have more of your skin lightly covered
instead of, you know, I was actually thinking about working in
the woods and as a logger here in Maine in the summer, you might
be in the woods. You're going to have chaps or you're going to
have Cutter's pants on. And that's covering a fairly sizable
chunk of skin with a fairly heavy fabric that's way more than.
And that 12-ounce cotton woven pant that you're going to have. So
it's going to have a different effect than, say, someone with
minimal or clothing that's not that heavy wearing a full face
respirator. So I think that's a good point. It's not just one
piece of PPE or PPE itself, but a combination of all that are
going to come together to drive [00:33:00] the heat stress
higher.


Thomas Bernard: [00:33:03] Yes, that's right.
And then getting to the issue of mitigation, if we work just in
the context of the job risk factors that we've been talking
about, you have to pair up your actions so that you're on
average, say, over the course of an hour, you get it within what
would be the occupational exposure limit. So if you're wearing
PPE, that's really interfering with sweat, evaporation, taking
some time where you can dock that in order to be able to cool
down will be important with the metabolic rate. If you're going
to have periods of high metabolic rate, you're going to have to
balance those with periods of lower metabolic rate or if you were
in a very hot environment, periods where that environment will be
a little bit cooler. But it's that combination of those three
[00:34:00] things that are going to dictate how it is. You can
mitigate that level of heat stress.


Pete Koch: [00:34:09] I think that's a good way
to think about it. And I think many times as I work with
employers, they're really looking for one solution. And when it
comes to heat stress, it's not just a single thing that you that
you're going to be able to do. It's an advantage that you get to
look at the combination of things and make some modifications.
But it's not like, drink water or go to the shady spot that's
going to be the solution. So there are different things that the
employer is going to have to look at. Kind of brings up a point.
I want to just kind of maybe jump back a little bit and talk
about what factors contribute heat stress. And as I was thinking
about outdoor activities, I was thinking about the flager on the
side of the road, standing there all day in direct sunlight. How
much does direct sunlight change [00:35:00] the impact of
temperature?


Thomas Bernard: [00:35:03] So the direct
sunlight, you know, you'd rather be obviously in the shade than
the sun, but the sun is going to make you feel warmer. So there's
going to be a sensation because it's heating the skin. But the
thermal load, if you will, is still going to be small compared to
even the metabolic rate of just standing there. All right. And so
it's important. And in the effect might be actually a little bit
of a side effect is that you're warming the skin, which means
you're going to bring a little bit more blood with the
opportunity, especially standing, with the opportunity for that
blood to pool down to the legs. And then you're going to feel
faint and then you might succumb to a heat syncope, which
[00:36:00] is a painting of that. All right. So, you know, just
building on your example of the flagger they're going to want to
walk a little bit or pump that blood back up to the heart, but
the sun is going to make them uncomfortable. It's not adding
substantially to the level of heat stress.


Pete Koch: [00:36:24] Gotcha. And again, it's a
combination of different things. Right. So thinking about that
flager again and that static posture of being there, gravity
always wins. So pulling blood down to the extremities, not
providing enough oxygenated blood back to the brain, we actually
talk about that from a fall protection standpoint. So, you know
what happens if you're hanging in a harness for too long? How
long are you going to be able to stay conscious in that
particular position without being able to move? And it's one of
the strategies for response after you've fallen to be able to
move to be able to get muscle pump, to help your heart [00:37:00]
move blood back up into the organs that need it to keep you, keep
you awake, keep you alive. So, again, the combination of
different things to look at, so movement to get the blood flowing
and in this case, not only for oxygen, but to help dissipate your
warmth back to all parts of the skin and not just the parts where
the blood's hanging out down in the legs, so interesting. As we
think about prevention, some more continuing down that track. Is
there reliable data to support effective regulations around heat
stress in the workplace and still trying to balance quality and
productivity at the same time? Because I know that's always the
thing. Like we have to have productivity, productivity,
productivity and quality and quality. But if the person's not
able to do it, you're not going to be able to manage either of
those. So is there good data to support that?


Thomas Bernard: [00:37:53] So the answer is yes,
and then maybe some of your listeners aren't going to want to
really [00:38:00] know the answer to the issue of productivity.
OK, so let's talk about two parts of what regulations and I'd
even broaden it to say what's good professional practice, OK,
whether there's a standard or not. So one is that we're going to
have to do exposure assessment. And is there good data to support
that need that? The answer is yes. And the primary data asks the
question, where can most people maintain thermal equilibrium? So
how can they tolerate that environment for long periods of time?
And you'll see these. Generally expressed as a WBGT limit at a
given metabolic rate, and then the side of that is, of course,
the increasing metabolic rates could lead [00:39:00] to a
reduction. And what that limiting WBGT will be and then adjusting
that for any kind of clothing that's being worn. So that's the
exposure assessment. The point being is that it's
well-established. We understand and know it. And it also follows
the public health model that we're protective of most people. And
we've already talked that there's a huge range. So we have to be
careful that we don't fall into the trap of face validity where
somebody will say, well, wait a minute, everybody, almost
everybody can tolerate something higher.


Thomas Bernard: [00:39:41] All right. But we
don't know who those people are and we don't know how much higher
than the other part is. What's the least you want to be doing to
manage those exposures? And so I have my I have my list
[00:40:00] of what you minimally have to do. And that falls into
training, which is just, you know, accepted gospel truth in any
occupational health and safety issue. I call them hygiene
practices, but there are things that individuals can do to reduce
their individual risk. Hydration is one example of hygiene
practice. Arguably, acclimatization in terms of adjusting
expectations is another hygiene practice. And then the third is
surveillance. And that's really knowing what your environment is
that a give them time because it does change during the course of
the day. And it's also medical surveillance. It's the employer
keeping track of even first day. So the data, so they can better
appreciate what's happening in their workforce. [00:41:00] And
then in the final thing is having an emergency response plan and
if you will, I'm going to go I'm going to go back to your example
of the harness and having fallen and now somebody is just sitting
there.


Thomas Bernard: [00:41:15] All right. I heard a
safety professional probably 20 years ago say, talking about a
fall protection program. And they said if your emergency response
is calling 9-1-1, you're in trouble. And that is also the case in
heat stress. If you think your emergency response plan is that
somebody is going to dial nine one and you have nothing else to
do, you're in trouble. Right. So it's those four components. It's
having the training. It's practicing heat stress hygiene, it's
doing surveillance, and it's having an [00:42:00] emergency
response plan. And that emergency response plan, in my mind, also
includes just first aid. Then I think in this way, what we've
done is put in the backstop just in case we've made a mistake
with our surveillance or we have someone who is heat intolerant
because our usual standards don't protect everyone it protects
ninety nine percent of the exposures or one percent of the
exposures is once during a summer per person. All right. So
that's not exactly overwhelming odds of protection. And so we do
need to have that backup. We do need to say, OK, when that person
slips through our protection, that we've got them covered.


Pete Koch: [00:43:00] Let's [00:43:00] take a
quick break. How hot is too hot, anyway, as we are hearing during
this podcast, often it's not as simple as looking at the
thermometer, humidity, airflow, the physical nature of the work
and how the person is equipped all play a part. Not identifying
and mitigating heat exposure in the workplace can cause serious
or even fatal illnesses and injuries because workers will react
differently to different conditions when hot environments are
identified in the workplace. Employers must be equipped to
respond appropriately for resources to help you identify and
respond to heat stress exposures. Check out the heat stress
resources from NIOSH through the Center for Disease Controls Web
site CDC.gov and search heat stress. If you're a policyholder
with MEMIC, you can sign into the MEMIC safety director and
search for heat stress to find more resources there. Now let's
get back to today's episode.


Pete Koch: [00:44:00] So I like that as
[00:44:00] we talk about those basic work practices, those are
the essential things that we need to do to make sure that we can
respond properly to heat stress in the workplace. So let's go
back and take training just as one of those pieces, because I
think training around heat stress is quite varied if it's done at
all in in different environments. So let's talk a little bit
about what might be important for an employer to do for training
for their employees around heat stress.


Thomas Bernard: [00:44:32] So training is going
to be much like an employer would do for every other health and
safety. So I always have to be careful to keep that perspective
that they've got more than one problem to deal with. But once we
work within that format is that you want the employee to be able
to understand their hazards and then make rational decisions
[00:45:00] about how to deal with those hazards to protect
themselves and protect others. So you want to educate them to
what are the factors that cause heat stress? So that's the
environment, especially the humidity, the work demands. And if
there are special clothing that they have to wear so they
understand how these contribute, then having a little bit of
basic understanding about what are the physiological responses so
that there is a cardiovascular demand and there is a demand on
water. We give up water from our body in order to cool ourselves,
hence the need for hydration. So they've got that rationale for
the hydration. Importantly then what they need to know or what
are the signs and the symptoms of heat related disorders so that
they can immediately recognize them. And we rely on people
[00:46:00] to recognize them in themselves. But very importantly,
we rely on people recognizing the signs in somebody else. And
these then go toward the early recognition of the disorder. Then
we can have the proper first aid or the proper response. So they
need education on what these are. So that leads to what's the
first aid, an emergency response plan.


Pete Koch: [00:46:28] I think that's great and
really kind of outlines well, it takes that training component
and it incorporates all of those other components into it. So as
an employer, really seeing it as not just a standalone piece, but
if you're going to have if you're going to have a heat exposure
within the workplace, then the training should include all of
those components all the way up into. What do you do as an
employee if you recognize this in one of your co-workers, which
is a key part. And we actually [00:47:00] talk about that quite a
bit on the cold side, like we talk about hypothermia, exposure,
because a lot of folks, you're not going to know that you are in
the early stages of hypothermia if you've got the fumble,
stumbles and mumbles. So it really relies on your partner, your
co-worker to understand what those symptoms are and start to
address those we're going to touch. I'm going to ask you another
question about cold stress here in a minute. But at the time of
this podcast, there's actually a bill within the Maine
legislature that's proposing setting a standard for maximum and
minimum temperatures for indoor places of employment. And I just
wondered, with all your experience around heat stress and how it
affects the person and the variability of that, what are your
thoughts about setting those limits and making them legislation
for state?


Thomas Bernard: [00:47:51] Again, I'm not
opposed to legislation. I think, in fact, legislation and the
actual rulemaking. The rules are [00:48:00] really very
important. And I am a proponent of these. There's just a couple
of things. First of all, I did a quick read of the brief
legislation that's in front of the Maine legislature, I presume
by maximums they're really thinking in terms of heat stress. And
when they talk about minimums, they're really talking about cold.
And these are really two different things. So let's talk first
about heat, I think heat stress has to recognize that there are
the three job risk  factors that we've been talking about
and therefore, any exposure assessment needs to be framed in the
way that we've been talking about. And you're not going to do
that by saying, here's the temperature. If you do that, you're
going to be setting a temperature so low, that everybody's
[00:49:00] going to fall under it. And I don't think there will
be very many people that are happy about that circumstance. For
cold stress, if I can just go there for a moment and you started
to allude to it. So I do want to come back. First of all, about
cold stress, humidity no longer plays a role, so it air
temperature and a bit air speed, but it's more nuanced than that.
So you talked about hypothermia and hypothermia. We worry a lot
about what is the temperature and then what is the clothing. And
really to manage that cold stress exposure, we have to have
enough insulation on to protect ourselves from hypothermia for
any given temperature and work demand because remember, you're
generating heat. And then what you want to do is preserve enough
of that heat that you don't lose body [00:50:00] temperature, but
then you need to allow the rest of it to dissipate.


Thomas Bernard: [00:50:05] And so adjusting
clothing, insulation and being in the skiing industry, you know
how to do that. And I'm not a skier, but I imagine going up the
chairlift, you're going to be all bundled up because your
metabolic demands are low and then you're going to loosen up your
clothing before you start heading down, because now your
metabolic rate is high. So you have to adjust the effective
insulation of that clothing. So this is key for managing
hypothermia. Then the other thing we worry about is actually a
localized effect. So it's getting frostbite or frost nip. And
that then is what is the air temperature and what is the air
speed, because that will dictate the rate of cooling of a patch
of skin. So in cold stress, we have both hypothermia managed by
clothing and we have local [00:51:00] effects that are managed
by. Basically, if you will, managing the wind chill, and that
works, the other thing that's worth noting from the safety point
of view is, remember, we talk that the risk and the probability
of an accident that could be an acute injury or loss of property
or however it might manifest itself, goes up with heat and it
does. But it goes up on the cold stress side and it goes up 10
times more. So cold stress in terms of having a risk associated
with accidents is much more of a worry. It's I think it's a worry
on the heat stress side, but it's an incredible concern on the
cold stress.


Pete Koch: [00:51:51] If I can ask a follow up
question around that, why does it go up so much more? Why do the
probability of accidents go up so much more [00:52:00] in cold
than it does in heat?


Thomas Bernard: [00:52:02] And I don't have a
clue.


Pete Koch: Fair enough.


Thomas Bernard: But I got to tell you, it's an
absurd phenomenon, right? It is there clearly enough that it's a
problem. And I reported on it in an aluminum smelter, which is
really a very hot place that if you're located in a northern
location with a lot of air ventilation and smelters require a lot
of air. When it gets to be zero outside or subzero, it gets
incredibly cold in there at that time. And so we saw the
accidents increase. But we're not the only investigators that
found it. There were many others, too, who observed the same
thing.


Pete Koch: [00:52:52] I've totally found that in
my experience with the ski industry as well, that I don't know
that I could have, from my experience, say that it went up 10
times. But [00:53:00] I do know that even with a little cold
stress. Your reaction time lessens physical reaction time, mental
capacity at a much lower rate than I think for heat stress. I
think your body can get warmer and still have a relatively
functional processing capacity whereas you start to get cold and
you start to shiver or you start to stop shivering, which is
worse, you're not able to function anywhere near as well as you
could just a few minutes ago before that that metabolic change
happened for you.


Thomas Bernard: [00:53:40] So if I can abuse
something that I told you earlier, we're tropical animals. So we
have learned to adapt, not learn to adapt. We have.
Physiologically, the capacity to deal with heat being tropical
animals, [00:54:00] we've relied totally on behavioral
modification to manage cold.


Pete Koch: [00:54:07] Yeah, that makes a lot of
sense, tons of sense. So I guess kind of coming back to that
legislative question then to have a hard and fast maximum and a
hard and fast minimum from a temperature and just looking at
temperature and they haven't even defined temperature in that
particular bill that's there. I think there's probably a lot more
work to do to make legislation functional for the protection of
employees that still allows quality and productivity to live
symbiotically in that.


Thomas Bernard: [00:54:39] Thank you for
bringing us back to the productivity. So let me get to that in a
moment. Yes. You know, there's an incredible amount of work that
staff and the Department of Labor are going to have to do to try
to actually make this workable. That that was a fine action by
the legislature, [00:55:00] if that's what they take. And other
than, you know, in my mind, I read that by I say, well, they've
given a command to the agency, develop something. The agency is
going to quickly discover that this is a more complex process
than that legislation would suggest. And that's fine. You know,
we rely on the rulemaking process to discover those things all
the time. The second part of this is that if you manage the heat
stress and I'm also an expert on the cold side, but the cold
stress, your quality of work is probably going to stay pretty
close to the site. But what's going to happen is that you are
going to have a decrease in productivity. And this is just simply
inevitable because you're taking physiological [00:56:00]
capacity and redirecting it from work to dissipating heat. You
simply can't avoid it. So from a compliance point of view, I
don't like thinking about compliance point of views, but it
frames it well enough to maintain that level of compliance by
necessity or your productivity is going to drop. How well you
manage that heat will tell you how much your productivity is
going to drop. And if you think you can beat that by saying, OK,
we will just pay people a piece rate, their productivity is still
going to drop. It might not drop as much, but I posit that I
study again to show even increased rate productivity drops. But
if you're not managing that exposure, what's happening is that
the workers are taking on more risk and they're not doing it
consciously. So that's not a willful taking on a risk. That's an
unconscious [00:57:00] take on of risk that will lead to a higher
probability of a heat related disorder and especially a heat
stroke.


Pete Koch: [00:57:12] I think that's a really
good point. That's because it's a fine line, internal perception
of where you are metabolically in your temperature. It's not
easy. So as you're working, you're going to feel hot. But that
moment that you go from feeling hot to not being able to manage
the load anymore is a pretty fine line. And then going from that
to heat stroke is an even finer line, and it's different for
every person. So it really does make sense to try to manage that
and knowing that productivity is going to have to suffer because
it's a math thing. When you kind of get to it, what goes in has
to come out. Otherwise the person is going to get hurt. That
takes us into and I think it's a good lead into what [00:58:00]
might be the appropriate medical response for heat stress. And if
we start to look at it from. All right, so we've done what we can
within the workplace, but this individual is not reacting well to
the mitigation that we've had. And they're starting to experience
heat exhaustion or heat stroke. And we're going to call 9-1-1. We
know that's an important part of the response, but it's not the
only part of the response. What's the appropriate response to
heat stress once an employee has reached the point where they
need intervention?


Thomas Bernard: [00:58:33] So if you'll allow me
to get away from the model that heat stress and the fact that now
they're experiencing heat related disorder, which is the
excessive strain, is that and pardon me, but that's just my
obsession. So it's staged. You know, if it's a mild heat
exhaustion it's going to be a symptoms driven identification
[00:59:00] and the risk. And if you will, that's the early
recognition. We like that. If somebody is reporting that they
feel fatigued and they're thirsty and we like that, dizzy maybe a
little bit of a headache, then they can stop work, go into as
cool places they can find and drink. And chances are within 15
minutes they're fine and they're fully recovered and ready to go
back to work. We like that. That's early recognition, early
treatment. And if they go into a more advanced so a severe heat
exhaustion, their body core temperature, we're not going to
measure the body core temperature, by the way. And I'm not
advising that, but it's going to be somewhere and still in the
vicinity of what we would expect. But the cardiovascular demands
are going to be huge. All right. So they're going to, again,
[01:00:00] report headaches and tired. You know, their blood
circulation is where we would want it to be. But now we're also
starting to rely on signs, OK, they're going to be wobbly.
They're just not going to be walking that straight line. We're
going to notice that drop and physical capacity. Then we have to
if they're not coming off the job to try to cool down, recover,
we need to pull them off.


Thomas Bernard: [01:00:29] Right. So this may be
where we're starting to make bad judgments. And in the buddy
system needs to see that and again, it's sitting in a cool place,
it's drinking fluids and keeping a close eye in severe heat
exhaustion. My friends in the sports area will take a towel
soaked in ice water, put it over [01:01:00] their head and
shoulders. And they use this not because it cools them better,
but it helps give them an idea about the severity of the severe
heat exhaustion. Right. So if they begin to feel better
relatively quickly, then they know they're dealing with heat
exhaustion. On the other hand, if they're not there, they're
keeping an eye on the symptoms for heat stroke. And this is
important now for heat stroke, nobody is going to report symptoms
so much like you use the example of the hypothermia. The same is
true for heat stroke. You're now not thinking this is now a
central nervous system failing your brain is letting you down.
And now this really requires your buddy to notice this. And in
the cases that I've worked on, it's often gibberish that they're
just [01:02:00] talking nonsense. They're going off and doing
things. They don't know where they are. They just threw down your
tools and left the job. OK, so behaviors that you just don't
expect and you've got to open up your head to what are behaviors
that are normal. And if anybody says I quit, the last thing you
let them do is leave.


Thomas Bernard: [01:02:23] All right. Because
this is going, you know the “Bernard Pointer” is this looks like
a heat stroke. Then the absolute best way to deal with that is
put them in a cold water or ice water immersion bath. So you want
to emerge and you'll see the old emergency medicine textbooks
say, no, no, don't do that. Now, clearly, all of the evidence is
ice water immersion is the best way to cool them down. Now, if
you're out doing the timber harvesting that you discussed,
[01:03:00] you know, hopefully you've got that one quart of water
per person per hour. You know, who's sitting there and you
probably have some left over. Hopefully it's cold. Well, you wrap
somebody in a tarp and dump all of those in alright. You do
whatever you can to cool them down. Right. And then you call
9-1-1. Notice that we're not calling nine one waiting that 15, 20
minutes, one hour for them to show up. And by the way, you want
to alert them that you're dealing with a possible heat stroke so
they can prepare to deal with that so that they can get them to
the emergency room. So that's part of the plan. And when I'm
working with but like right away maintenance, where they could be
almost anywhere then knowing where you are and going over that
[01:04:00] emergency plan, making sure you have cell phone
service and everything else that you need, becomes part of that
tool box safety meeting prior to any job that you begin.


Pete Koch: [01:04:12] Those are great points,
and it's interesting how a lot of those points are relative to
really any job that has a significant risk of serious injury,
whether it be fall protection or you're working around heavy
machinery. Working alone is not the best thing, because, again,
if you're risk assessment about the job that you're doing
indicates that you're going to be in a high heat environment, you
have the potential to not understand your own symptoms. So having
someone there that can help is a pretty key part. And I do think
that people do miss that part of their hazard assessment, like
they talk about the environment, but they think about weather
like high winds or something unexpected. But you can have a day
that's, you know, in the high 90s and very [01:05:00] humid and
very close and still. And you could have a significant heat load
on the person and there could be a lot of heat stress. And then
the person can experience a lot of heat strain from that. Great
recap on the medical response there.


Thomas Bernard: [01:05:14] And I just want to go
back and reiterate about the buddy system, because when you do,
you know, there's reports in the literature of these cases of
heat strokes and a number of times that somebody wanders off and
dies alone. You know, even though I'll tell people you never
leave anybody alone.


Pete Koch: [01:05:38] It's a great point. And
that's an interesting point, too, because a lot of folks were
like, oh, he just needs his space. He needs his time. Well,
understand the environment that they're in and what they're
responding to, because it might not just be they need a break
from whatever they're doing, like you said. What's abnormal about
their behavior? Is this something that they typically do or is
this something very different than they've [01:06:00] presented
in the past? And if it is, I think you said it was the “Bernard
Pointer” don't let them leave. Right. I like that.


Pete Koch: [01:06:07] So we're kind of getting
towards the end of the podcast here. I do have a couple last
questions. And one of them I well, it's a big question, so I'm
not sure if it's fair, but I'm going to ask it to you anyway. So
what do you know now about heat stress that he had wished you had
known when you first started out when like when you were in the
working with the mines and in the smelters and all that before
you came to your position as being a professor? What did you what
do you know now that you wish you had known then?


Thomas Bernard: [01:06:36] Just about everything
I know now. I wish I had known then I so I don't have a good
answer. I've been asked this before and in some variation or
another. And one response that I have is that every time I work
on a case, for instance, I learn something new and I put that in
my bucket [01:07:00] of knowledge. So I've got an accumulation of
thirty or more years of this. Then, you know, I also think about
this question all the time because I am a researcher that's
beyond teaching. I investigate and we always are asking ourselves
questions to this very day. We're rethinking what it is we know
about acclimatization and the associated risks. What is it that
we know about time weighted averaging and recently I've been more
staging and thinking about severity. So we always think in terms
of that hour after hour for an eight-hour day. But, you know, one
of the things that we found is, for instance, of three degrees C
I'm sorry, I think in degrees C increased, which is not huge
changes the response of an individual from [01:08:00] being able
to just thermal regulate to putting them into a situation where
they're where they're at high risk for heat stroke doesn't it's
not a big change from an upper limit to what can be a very
serious outcome and how we can begin to do the risk assessment.
So I'd like to say that you know every year I learn something new
and I'm hoping, you know, next year, if you ask me that question,
I've got more things to add to that list.


Pete Koch: [01:08:32] I think that's awesome
with all the knowledge that you have. And then just being open to
that. There's something else out there that we just don't know
that can shed a little bit more light on what you already know to
give you insights. Some places. I think that's an awesome
response Tom. So thanks for that. Is there anything that I should
have asked you? But I didn't ask, is there something else that
you want to reflect on for us?


Thomas Bernard: [01:08:55] So the answer is we
talked about the four [01:09:00] essential things. I want to go
back and first put a context. If you suspect you have heat
stress, those are the four things you need to do. That's the
training the hygiene practices. Surveillance and having a first
aid emergency response plan, when you get up to where you're
reaching an occupational exposure limit, you also need to follow
that typical hierarchy of controls. We're not likely to be able
to do elimination and substitution, but there are engineering
controls that are effective and administrative controls and there
are personal cooling systems that work well. I want to go back,
though, to the first four. And it's the hygiene practices,
hydration we've really talked about. And it is about anywhere you
go, people are going to talk about it. It is drinking cool
flavored drinks doesn't [01:10:00] have to be electrolytes, but
we know that they drink more electrolyte drinks than anything
else. So I think that it just happened that there have been at
least palatable water, its direction or self-determination, so
that if you are feeling well, there ought to be a freedom to go
recover. And most employers that I work with, you know,
acknowledge that they do that. But it's getting the people to
take advantage of that that tip, and especially if they're on
piece rate, that the conflicting goal they ought to know about,
if they've got chronic health issues, their personal care
physician should clearly know that they work in a heat
environment because there's not a disease or treatment that
probably won't interfere with thermal regulation.


Thomas Bernard: [01:10:50] The for acute
illness, you know, the public health person to me to stay home
because you're going if you go to work, you're going [01:11:00]
to infect somebody else. But if you do remember that any nausea,
you're not going to drink and you're not going to eat well,
vomiting and diarrhea are going to dehydrate you. Fever is going
to reset your thermal regulatory system. There's just a whole
bunch of things that say you shouldn't do that and that a good
diet, well balanced diet, no fad diets, getting plenty of rest
don't do drugs are, you know, good advice. And I probably forgot
something in there. But that gets I think, you know, an the
acclimatization, adjusting your expectations, you're not going to
run with everybody else. Until you get used to working in the
heat. And even then, there's somebody who's going to be less
tolerant than everybody else. So there's going to be somebody who
can't keep up with everybody else.


Pete Koch: [01:11:53] Those are all great tips.
And some of them don't get pushed hard enough within the
workplace. And I think that having [01:12:00] employees
understand and then have a culture that gets them to feel that it
is OK to not be first, especially when you're in that
acclimatization process and that there's always going to be
someone who is going to be better. It's not that you shouldn't
try to be better, but know that heat is going to be in effect
here. And it's going to effect everybody differently. And it's
not something that you may be able to overcome in the same manner
that someone else is. And then you really hit the nail on the
head there, whether it's piece work or something else. But that
permission to just say, hey, I've recognized in myself, that I've
hit the limit and I need to go and cool down before I can come
back and be a functional part of this job team again. And that's
a really key part. And I do think that's missed often in our
training or our discussions with our employees. You see it often
when you walk into different places. And there's just something
odd about the culture. They're like people are working super
hard. But you're also looking at looking at people thinking
[01:13:00] you probably need to step away from that machine for a
little bit and take a break, reset and come back to it because
you're bound to get injured. Good, good. Really good points
there, Tom. Thank you for those. I think I could talk to you for
another few hours, but. Well, I think we're going to have to end
it here pretty soon


Pete Koch: [01:13:18] If our listeners are
interested. And I know they're going to be, about finding more
out about heat stress and your work around heat stress, where can
they go?


Thomas Bernard: [01:13:27] That's great. I'm
always willing to kind of help where I can. I'm not going to send
you to my website because I've got to get it back right again.
The systems people moved on a server behind on that. But there's
some materials that I can make available.


Pete Koch: [01:13:47] There are other
organizations like NIOSH that have done research on heat stress
and how to prevent it within the workplace, too. So but there's
other places to go as well. So [01:14:00] besides NIOSH, are
there any other organizational places or websites that folks can
go that you would recommend?


Thomas Bernard: [01:14:07] Yeah, a great
resource is NIOSH. They've revisited their criteria document
three and two types, so they issued one, revised it once and
revised it again, that's almost unheard of. So it really
reflects, I think, the current thinking. Their most recent
revision is 2016. So anybody serious about heat stress
management, she should avail themselves of the NIOSH criteria
document dated 2016. If you just do an Internet search, you're
likely to find it. OSHA and NIOSH have materials on heat stress
on their websites and I think they're generally pretty good. My
only hesitation [01:15:00] and it’s a modest hesitation is that
they will in some areas talk about stages of heat reflected in
the heat index. And I think their ideas generally right. I'm not
sure that I totally agree with their thresholds. I think a couple
of them are too high in a couple of them were too low. But the
idea, you know, the content for training programs and heat alerts
and all of the things that they discuss are really very sound
approaches, because I've been on the physical agents committee
and the ACGIH. But I'll remind you that the ACGIH has a TLV for
heat stress and strain and associated documentation so members
can easily get a copy of this and nonmembers it is available for
purchase. And I'll [01:16:00] give a heads up. We're in the
process of doing a major revision not of the thresholds, but the
associated documentation. So in a year I think it's going to be
even better.


Pete Koch: [01:16:12] What we'll do is we'll
take those, we'll take those documents and we'll put those links
on to the podcast website. So you go to MEMIC.com/podcasts.
They'll be able to see the transcript from this and then they'll
also be able to grab those resources. I think that's great. You
spent a ton of time with us and I really, truly appreciate this
conversation. Tom, it's been fantastic to have you on and share
your expertise with us. Really.


Thomas Bernard: [01:16:39] It was fun to do it.
So I appreciate the opportunity.


Pete Koch: [01:16:45] And Tom, thanks again for
joining us. And thank you to all of our listeners out there.
Today on the MEMIC Safety Experts podcast, we have been speaking
about heat stress with Thomas Bernhard, Ph.D. Tom is a professor
at the University of South Florida College of Public Health
[01:17:00] and the director of the Sunshine ERC a NIOSH Education
and Research Center. If you have any questions or would like to
hear more about a particular topic on our podcast, email me at
podcast@MEMIC.com. Also, check out our show notes at
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