Is It Hot In Here?
by Janet L Keyes, CIH and Carol Keyes, CSP
This past April, OSHA, a National Emphasis Program on heat, automotive repair and maintenance made the list of targeted industries. Why? Because we know summer temperatures have been rising. We’ve seen an increase in heat-related illnesses and fatalities. Even though Minnesota has had snow in June, we’re not immune.
Minnesota’s weather is fickle, with temperatures in the 90s one week, followed by highs in the 70s. This kind of roller coaster does not give us time to acclimate, to let our bodies adjust to the heat. That makes hot weather more dangerous.
“It’s not the heat. It’s the humidity.” That’s not (quite) true. Humidity makes high temperatures more dangerous. People cool off by sweat evaporating from their skin. If the air already holds a lot of water, sweat doesn’t evaporate. But the air temperature and humidity aren’t the only factors that go into heat stress.
What people wear makes a difference. A painter’s spray suit or a body tech’s welding jacket increases heat stress. So does a respirator, especially a negative pressure respirator such as the cartridge respirators worn by many painters and body techs.
Air movement can make heat less of a concern – or make it worse. If the air temperature is above skin temperature (usually 95°F), more air movement can make people hotter.
Heat sources, such as a booth in bake cycle or sun shining through windows, add to the heat load. The work effort has a huge impact on heat stress. Someone working hard is generating more internal heat.
Personal factors, such as physical fitness, medications, age and genetics, have a lot to do with how well people handle heat.
How do you make sure employees stay cool?
• Train employees on heat stress, preventive measures and first aid
• Teach employees to watch for signs of heat stress
• Provide water
• Provide breaks in cool areas
• Provide fans. Make sure they’re grounded and in good condition
• Allow time for acclimatization of new or returning workers
Write your plan down. That’s the basis of a heat stress management program. It does not have to be complicated.
What areas in your shop are air conditioned? With doors opening all the time, many shops are not air conditioned but offices and break rooms probably are. Do you allow employees to take breaks in cool areas? If it’s hot, encourage that. Consider providing ice pops or other cool treats to give people incentives to use the air-conditioned areas.
Encourage drinking (of water) on the job. While there is the risk of contamination when food and beverages are consumed in chemical use areas, closed containers are okay. Water bottles with covered mouthpieces should be allowed. And remember – no storage of chemicals, like oil or antifreeze, in old beverage containers. You could provide flavored waters or sports drinks to encourage drinking. Sports drinks are usually high in sugar, so they should not be the first or only beverage choice.
Do you allow employees to take more frequent breaks, especially on the first hot days? Heat causes fatigue, so employees may not be moving as fast when it is hot and humid.
Remind employees to watch out for each other and check on employees frequently. Everyone should know the signs of heat related illness. And if anyone suspects heat illness in a coworker, act fast.
The National Weather Service publishes a heat index, a rough guide to the dangers of heat. It factors in temperature and humidity. But it doesn’t consider whether you’re working in full sun, what you’re wearing or how hard you’re working.
The American Industrial Hygiene Association (AIHA) introduced a heat stress app a few years ago. Developed by occupational health and safety experts, this free download (available for Android and Apple) allows you to customize information for a more accurate heat stress indicator. You can specify whether the work is indoors or outdoors, how heavy the workload is, and what type of work clothing is used. It will then pull data from the National Weather Service to calculate a heat stress risk index. It also has information about the hazards of heat, control measures and what to do in a heat emergency.
To download the app, search for AIHA heat stress. If you use this free app, we encourage you to send feedback on it, either directly to AIHA or to Janet Keyes, so the app can be improved.
Want more? Check out the July 2026 issue of AASP-MN News!