Heat can make a worker sick in a few hours, and it can kill. Heat illness happens every summer in the United States, on farms and building sites, in warehouses and kitchens, on delivery routes and in laundries. It also happens indoors, where no sun shines.
This course gives awareness of the hazard, the rules and the first response. It is not medical advice.
How the body handles heat
Your body makes heat all the time, and it makes more when you work hard. To stay near its normal temperature it must lose that heat. It does this mainly by sweating. Sweat cools you only when it can evaporate.
Trouble starts when the body cannot lose heat fast enough:
- the air is very hot,
- the air is humid, so sweat does not evaporate,
- the sun shines on you, or a machine, oven or furnace radiates heat at you,
- you wear heavy clothing or protective equipment that traps heat,
- the work is hard, so your body makes a lot of heat.
When heat builds up, the body strains. The heart beats faster, you lose water and salt in sweat, and your thinking can slow down. If the body temperature keeps rising, the result is heat stroke, a medical emergency.
Who is at higher risk
Anyone can be affected, but some people are at more risk. CDC/NIOSH lists these risk factors:
- lack of acclimatization: the body is not yet used to the heat,
- dehydration, and not drinking enough during the shift,
- hard physical work and the use of protective equipment,
- some health conditions and some medicines,
- older age, pregnancy, and a previous heat illness.
Ask your own doctor or pharmacist if a medicine you take makes heat harder for you. That is a personal question, and this course cannot answer it.
Heat is also a safety hazard
Heat does not only make people ill. NIOSH also notes that heat can lead to injuries: burns from hot surfaces and tools, slips on sweaty hands or floors, fogged safety glasses, and dizziness that leads to a fall or a mistake near machinery.
Outdoor and indoor work
Heat illness is not only an outdoor problem. Indoor workers can be at risk where the building is hot or the process makes heat:
- kitchens, bakeries and laundries,
- foundries, glass and metal plants,
- warehouses and factories without cooling,
- hot vehicles and delivery vans,
- attics, boiler rooms and other enclosed spaces.
Heat illness can come quickly, and it hides
A worker does not always notice the early signs, and may not want to say anything. Some people keep working because they do not want to let the team down. That is why this course teaches two habits:
- Know the early signs, so that you stop before it gets serious.
- Watch each other. A buddy often sees confusion or slurred speech before the person does.
What to remember
- The body cools mostly by sweating, and sweat needs to evaporate.
- Humidity, sun, heavy clothing and hard work raise the risk.
- Heat illness can happen indoors as well as outside.
- Lack of acclimatization is a major risk factor.
- Heat also causes injuries, not only illness.