In general, a worker’s body protects its core temperature against high external temperatures by changes in blood circulation and sweating. When workers perform physical activities—just like an athlete playing a game—less blood is available to flow to the skin to dispose of body heat. Sweating kicks in and helps cool the body. Fluids and salts are lost through sweating and need to be replaced by drinking more water, sports drinks with electrolytecarbohydrate solutions, etc.
Several worker characteristics also come into play when it comes to heat exposure, including age, weight, physical fitness and health status, medications and alcohol intake.
Workplace factors also combine to determine how workplace heat affects work—including temperature, humidity, radiant heat (such as from the sun, a hot engine or a welding torch), air circulation and workload (level and type of activity). When these factors are in play, care needs to be taken to allow the body to maintain a sufficiently cool state and avoid several types of heat-related illnesses. Heat related illnesses include (and may occur simultaneously):
- Heat stroke, caused when the body’s sweating mechanisms fail;
- Heat exhaustion, caused by insufficient cooling of the body;
- Prickly heat (i.e., heat rash), caused by sweat ducts becoming inflamed;
- Heat cramps, caused when body replaces fluids in the muscles too quickly without the proper balance of salt;
- Fainting caused by over-dilation of the deep blood vessels in the body, resulting in a rapid decrease in blood pressure.
Workers with these conditions may become irritable, confused, giddy, nauseous or dizzy, and may experience headache and muscular pain and/or fatigue. Pulse may be weak and slow, and blood pressure often drops. The worker’s complexion will often be pale or flushed. Often the skin will be moist and clammy, except with heat stroke, when the body fails to sweat.
- What are the basics to help protect workers from the heat?
- Wear light, loose-fitting, breathable clothing such as those made of cotton.
- Understand how personal protective equipment such as work suits can induce heat-related illnesses.
- Drink plenty of water or electrolyte-carbohydrate solutions before thirst sets in.
- Eat smaller meals before work.
- Avoid caffeine, alcohol or large amounts of sugar.
- Take frequent breaks out of the sun or in cool environments.
- Ask health care providers if medications have negative side effects when body temperature increases. IBI