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Why You Should Always Let Your Workers Acclimate to the Heat

By Bryan McWhorter
Published: July 10, 2019
Key Takeaways

Your body needs to adjust to the heat. By allowing it to acclimate, you reduce your risk of suffering from heatstroke and other heat-related illnesses.

Caption: Outdoor workers Source: ktasimarr / iStock

If you ever got used to working in a hot environment like manufacturing or outdoors in the hot summer sun, you know what happens when you go on vacation for a week. Once you get back to work, the heat can seem unbearable.

That's not just your perception. It really is less bearable than it was before. That's because you lost your acclimation to the heat. Your body needs more time to adjust to the hot environment.

How Acclimation Works

It is essential to understand that our bodies acclimate to heat. Employees who are new to working in heat need time to adjust. A heat-acclimated body and a non-acclimated body are two very different machines.


According to OSHA, it can take up to a week for workers to get acclimated to the heat under normal circumstances. There are a number of factors involved, including how strenuous the work is and how long the exposure lasts. However, people generally feel better and have less discomfort by day five.

(Learn more in Heat Stress: Indoor vs. Outdoor.)

Your body adjusts over time as you work in the heat. You can handle the heat more efficiently and can work longer without as much danger of succumbing to heat-related illnesses.

The fitter you are, the more quickly you will acclimate. However, fitness is not the same thing as heat acclimation. An athlete at the top of their game must still acclimate like everyone else – they'll just do it more efficiently and more quickly than most of us.

(Find out What Athletic Research Can Teach Us: 5 Tips for Optimal Hydration on the Job.)

Benefits of Acclimation

When you are properly acclimated to the heat, you will experience:

  • Reduced core body temperature
  • Reduced skin temperature
  • Improved efficiency in sweating (start sweating sooner, higher sweat output rate)
  • Improved skin blood flow (this releases heat from the body)
  • Lower metabolic rate (muscles burn less glycogen and your body works more efficiently)
  • Cardiovascular stability (heart rate decreases)
  • Fluid balance (thirst improves and fewer electrolytes lost)

(Learn more about Electrolytes: What They Are and Why They Matter for On-the-Job Hydration.)

When it comes to heat-related illness, it's all about prevention, including acclimation.

According to a report published by the EPA in 2016, heat is the leading weather-related killer in the United States. However, most of these deaths are preventable through training, outreach, and intervention.


Our bodies are adaptable, but we need to understand our limits and know the warning signs to before the onset of heat illness.

With time and exposure, our bodies gain what is referred to as an acquired thermal tolerance that allows us to work, exercise, and play in the heat with less chance of heat-related illnesses. We still need to understand and follow a game plan for handling heat, such as frequent breaks in the shade, hydration, and proper clothing (moisture-wicking fabric allows sweat to evaporate and cool the body). And if we take time off from working in the heat, we must give ourselves time to reacclimate.

Our bodies are amazing machines that are adaptable to hot environments. We need to give our bodies the required time and allow ourselves to ease into hot work environments.

Acclimation can mean the difference between a safe workday and one that ends in heat exhaustion or heat stroke. Never skip over that critical process.


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Written by Bryan McWhorter | Lead Safety Advisor, Author, Writer, Speaker

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Bryan McWhorter is a safety professional with eight years of experience in driving and teaching safety. Bryan gained his knowledge and experience as the safety officer and Senior Trainer for Philips Lighting. Philips is a strong health and well-being company that promotes a safety first culture.

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