Are You Affected By Heat Illness?

Scientists don’t yet know why some people become seriously ill while exercising in hot weather, and others don’t. It is believed that exercise-related heat illness is caused by the sizzling rays of the sun beating onto an athlete’s skin, causing overheating from the outside in, and contributing to dehydration, which is the basic cause of heat problems.

This tells us about becoming sick directly from thwe hot whether but does not explain why athletes develop heat illness on overcast days, when sunlight isn’t directly reaching them. They’ve also been known to become ill on relatively cool days, when temperatures are below 80 degrees. And many collapse despite being fully hydrated.

Scientists have a pretty clear picture of what happens inside these athletes as they exert themselves. They bake. Muscles in motion generate enormous amounts of energy, only about 25 percent of which is used in contractions. The other 75 percent or so becomes body heat.

According to a 2007 position paper from the American College of Sports Medicine about heat illness, exercising can raise core body temperature by almost 2 degrees every five minutes, “if no heat is removed from the body.” Meanwhile, sunlight and high air temperatures do contribute to the problem, although not to the extent once believed, by increasing skin temperatures. Humidity also plays a villainous role, slowing or preventing the evaporation of sweat, one of the human body’s main mechanisms for removing heat.