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Heat Stress: 7 Minutes of BS (Building Science Syncopated)

Too much of a good thing can kill you. Including sunny weather
July 27, 2023

This episode features Brenda Jacklitsch, a Health Scientist with National Institute of Occupational Health and Safety breaking down the topic of heat-related injuries which can creep onto the jobsite while you're not looking.

What heat stress is:

heat stress | hēt stres (noun)

"A net heat load to which a worker is exposed from the combined contributions of metabolic heat, environmental factors, and clothing worn, which results in the increase in heat storage in the body."

Brenda Jacklitch, Health scientist, NIOSH

Too much heat stress can increase the risk for experiencing a heat-related illness such as heat stroke, heat exhaustion, heat cramps, and heat rash.

How heat stress works:

You can overheat due to the ambient temperature, the clothing you are wearing, or your metabolism. When you do work, your body temp goes up. And it goes up faster if you put on a Tyvek suit and climb into a hot attic to do the work.

When the body becomes too hot, the brain will tell the skin blood vessels to dilate and the sweat glands to start sweating.

The sweat then evaporates and this cools the body and allows the body to release the excess heat.

And this cools the body.

A critical part of that first sentence is that the brain tells the body when to cool off. The other important part is that multiple mechanisms work together to heat people up.

Some risk factors that can impair the body's ability to cool down include high humidity, dehydration, PPE

PPE is government-speak for Personal Protective Equipment—I had to ask too.

PPE, or clothing that is worn, certain medications and health problems, advanced age, and not being acclimatized.

Why heat stress matters

So, many workers are out there and they're in the heat. They're doing hot jobs that are causing them to exert themselves physically and so that's creating that metabolic heat that builds up, and then oftentimes they get used to it and they think…

"Oh, just a few minutes longer and then I'll take a break,"

… but sometimes in those next few minutes that's all it takes to reach that stage of overheating and then suffer some of these really terrible consequences.

These heat-related illnesses and their outcomes can vary, ranging from temporary discomfort to death.


You can die from overheating.

How to avoid heat stress

Some recommendations that can be applied in a variety of work situations include:

Limiting time in the heat and increasing recovery time in a cool environment.

Take breaks, and get out of the sun

Increasing the number of workers per task, and assigning buddies

Keep an eye on each other’s mental state and water level

Providing water and encouraging workers to drink

Don't wait until you are thirsty because then it is too late.

Developing a plan to acclimatize workers, and training supervisors and workers about heat stress, heat related illness symptoms, first aid, and risk factors.

Understand the risks, ease your way into hot conditions, recognize the symptoms, and know the first aid needed in an emergency.

In a nutshell,

If a worker is feeling ill while doing a hot job, they need to stop, cool down, and rehydrate.

Supervisors and buddies should be monitoring how everyone is feeling throughout the shift and encouraging rest and hydration breaks.

A worker showing signs of heat stroke or severe heat exhaustion should be considered a medical emergency.

Call 911 and cool the worker down as quickly as possible, such as by drenching them with a water cooler or immersing them in an ice bath.

You now have an excuse to dump a bucket of Gatorade on your boss—provided the boss is acting incoherently. Maybe I should re-phrase that.

It is a good idea to have a big bucket of water available for emergency cooling.

A lot of heat-related illnesses kind of start off with somebody just not feeling right, they feel a little bit off. They may start sweating a lot,


their skin may start to redden.

—Flushed skin may be a sign of overheating

A lot of times people get thirsty, but by the time you're thirsty, you're usually considered already dehydrated.

Very quickly you can escalate from the beginning stages of heat exhaustion and go into heat stroke. And so, once you're in heat stroke that is definitely a medical emergency.

At that point you could lose consciousness and your body functions could actually start shutting down.

This is where the earlier comment about the brain telling the body what to do becomes important. Because the brain gets too hot to tell the body to cool down, or really to do anything.

If you're reaching those stages of heat stroke, there's a possibility that you may die.

I just want to verify that heat stroke can cause a person to die

Yes, absolutely.

And that's one of the very scary things about heat stress, and so the best thing to do is to call 911 and to immediately start cooling the person down as quickly as possible.

With a Gatorade bucket.

Remember it is often three things combining: metabolic heat, environmental heat, and clothing that causes you to heat up.

NIOSH does recommend the use of water-cooled and air-cooled PPE and vests. There's a lot of options you can find online in different workplace stores and stuff, where you can buy this extra equipment.

However, we know a lot of businesses, especially small businesses, may not have the financial resources to supply all that sort of equipment to their employees.

Fortunately, you can soak a bandana in your boss's Gatorade bucket and wear it around your neck.

Just don't tell her you heard it here.

Yeah, things like towels or soaking bandanas in cool water and wearing those around your neck, that can help to some extent.

OK, I guess you did hear it here

The best thing though is to really to try to take enough breaks and remember to rehydrate throughout your work shift so that your body continues to stay at some sort of cooled level.

On your breaks, don't sit in the sun. Go into the basement or sit in a truck

... and turn on the AC for 10 to 20 minutes to cool down, that would be optimal.

And that is an optimal way to cool down this conversation about heat stress. Remember, you get paid for what you do and what you know. And sometimes what you know can save a life.

We'd like to thank the National Institute for Occupational Safety and Heath for lending us a health scientist and wading through our podcast puddle.

7 Minutes of BS is a production of the SGC Horizon Media Network.

Related information on heat stress:

Image: Guian Bolisay via Wikimedia Commons

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