precautions to take while exercising in the heat

During the summer, physical activities are often complicated by environmental conditions. High temperatures and humidity add to the demands put on the body by exercise. Complications due to excess body temperature, such as heat exhaustion and heat stroke, can be serious. Between 1968 and 1987, 50 high school and college football players died as a direct result of heat-related disorders. Although the number of deaths per year has declined, fitness professionals still need to educate clients how to safely exercise in the heat.

When air temperature is greater than body temperature, the body absorbs heat from the environment. On warm days, radiation from the sun also contributes. Heat is gained from the reactions of energy metabolism. When muscles become active, they generate a tremendous amount of heat. During a vigorous aerobic workout, the metabolic rate can increase 20 to 25 times above basal levels. If cooling mechanisms didn't exist, body temperature would increase 1.5 to 2 degrees F every five minutes.

Luckily, our bodies have several cooling mechanisms. Evaporation provides the major defense against overheating. Our bodies have approximately 2 to 3 million sweat glands that secrete a weak saline solution. The skin is cooled when sweat absorbs heat from the body and evaporates. It's the evaporation of sweat that has cooling power. When it eventually falls from the body, it is wasted and doesn't help reduce heat.