114: Occupational Heat Exposure

What is occupational heat exposure and how to avoid it.
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In 2014 alone, 2,630 workers suffered from heat illness and 18 died.

It’s almost summer and temperatures are on the rise. So, this is the perfect time to start planning to protect your employees from heat related illness and injury.

This subject that is often overlooked, and it’s not just a summertime issue. Employees are exposed to high heat all year, both indoors and out.

In 2014 alone, 2,630 workers suffered from heat illness and 18 died.

Exposure to high heat can come from:

  • High air temperatures
  • High humidity
  • Radiant heat sources
  • Direct contact with hot objects, and;
  • Strenuous physical activity

Indoor heat exposure exists in a lot different businesses from restaurants to factories.

Outdoor heat exposure exists whenever you have employees working… you guessed it, outdoors, in hot weather, and in the direct sun. The construction, oil and gas, landscaping, and painting industries are just a few examples.

As an employer, you are required by the Occupational Safety and Health Administration to protect your employees from heat exposure.

How your body regulates core temperature:

Your body has 2 ways of keeping you cool. Circulating blood to your skin and sweating.

When your blood becomes too hot, the blood vessels in your skin open up allowing blood to pass into the skin where it becomes cooled. That’s what causes flushing of the face.

I’m sure you already know that sweating works by evaporation, and evaporation only works if the humidity level is low enough.

But did you know that Charles Blagden, a British physician and scientist conducted several experiments showing just how effective sweating works?

He called it “Experiments and Observations in an Heated Room”, and he became the first person to explicitly recognize the role of perspiration in our bodies thermoregulation

Blagden, and his co-experimenters (which included a dog), held several hot room sessions over the course of two years. By the final session the room temperature was 260 degrees. They had meat cooking in the room and they hardboiled and egg; and even though the men were extremely uncomfortable, they were uninjured, without even a rise of body temperature.

At least, that’s what Blagden claimed in his report to the Royal Society in 1775.

We have two million sweat glands in our skin, capable of producing massive amounts of water. It was the sweating and evaporation that cooled the Blagden experimenters’ skin, preventing them from being cooked to death.

According to Medline Plus, an average of 34 ounces of water are evaporated from your skin daily.

So, it’s super important to replace the water and salt that you lose through sweating.

Heat related illness:

Just because Blagden and his merry crew of volunteers survived a 260 degree heat room doesn’t mean the risk of serious illness or death doesn’t exist where the heat index is only maxing out at say 112 degrees, as it did for a 56 year old agricultural worker in North Carolina.

The National Institute for Occupational Safety and Health provides this example.

On the third day of work, an employee started work at 6:00 a.m. and took a short mid-morning break, and a 90-minute lunch break. In mid afternoon, a supervisor observed the man working slowly and reportedly instructed him to rest, but the man continued working. An hour later, the man appeared confused and coworkers carried him to the shade and tried to get him to drink water.

He was taken by ambulance to an emergency department, where his core temperature was recorded as 108°F and, despite treatment, he died.

On the day of the incident, the local temperature was 93°F with 44% relative humidity. The heat index that ranged between 86–112°F.

Heat-related deaths often occur in occupations where workers are performing tasks in hot environments, causing them to build metabolic heat faster than their bodies can release it to cool down.

And when that happens, your core temperature will rise along with your heart rate. After that, you’ll start to lose concentration and you’ll have difficulty focusing. If you’re doing risky work, that’s not good. If you get sweaty palms, tools can slip. If your safety glasses get fogged up or wet, you won’t be able to see so you’ll take them off and now your eyes are unprotected. If you get dizzy, you might fall.

Next, you’ll get irritable or sick and then you’ll faint, and you might die if you’re not cooled down.

Heat-related illnesses include rash, cramps, exhaustion and stroke, and it’s the heat stroke that will kill you. Needless to say, if you see symptoms of heat stroke, get immediate medical attention.

For a fact sheet with the symptoms and first aid treatment, head on over to smallbizbrainaic.com and click on podcasts or click on the search icon in the menu bar and type 114….and you’ll find a link in the show notes.

How to protect your employees from heat-related illness:

So, if there is any heat exposure in your business, indoors or out, you must implement a heat-related illness prevention program, and here’s what it needs to include according to the National Institute for Occupational Safety and Health:

    • Training for supervisors and workers to prevent, recognize, and treat heat-related illness.
    • Implementing a heat acclimatization program for workers.
    • Providing for and encouraging proper hydration with proper amounts and types of fluids.
    • Establishing work/rest schedules appropriate for the current heat stress conditions (an industrial hygienist may need to be consulted).
    • Ensuring access to shade or cool areas.
    • Monitoring workers during hot conditions.
    • Providing prompt medical attention to workers who show signs of heat-related illness.
    • Evaluating work practices continually to reduce exertion and environmental heat stress, and;
    • Monitoring weather reports daily and rescheduling jobs with high heat exposure to cooler times of the day

And your employees should:

    • Drink water or other liquids frequently enough to never become thirsty (about 1 cup every 15–20 minutes). Hydration is the most important tool in preventing heat-related illness, and workers should try to be well-hydrated before arriving at work.
    • Eat during lunch and other rest breaks. Food helps replace lost electrolytes.
    • Wear light-colored, loose-fitting, breathable clothing such as cotton. Avoid non-breathable synthetic clothing.
    • Wear a wide-brimmed hat when possible.
    • Take breaks in the shade or a cool area when possible.
    • Be aware that protective clothing or personal protective equipment may increase the risk of heat stress.
    • Monitor their own physical condition and that of their co-workers.
    • Tell their supervisor if they have symptoms of heat- related illness.
    • Talk with their doctor about medications they are taking and how the medications may effect their tolerance of heat.


About the author, Thomas

I have 20 of years insurance industry experience in C-level management, focusing on all aspects of workers compensation, risk management, loss control, employee benefits, HR, payroll and professional employer organization (“PEO”) operations. Currently, I am the owner and CEO of Humanly HR, and founder and host of SmallBiz Brainiac; a podcast providing employer intelligence to small business owners.

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