Heat illness in the athlete.

Heat illness is one of the most common causes of disability in American football and there are frequent deaths caused by heatstroke. A better understanding of the physiology of heatstroke has changed the manner of the approach to heat problems in the past 25 years. Sweating is the way the body dissipates the internal heat produced by muscular exercise. Since sweat is hypotonic, the result of excessive loss of weight through sweating is a water deficit in the body. The clinical disorders resulting from exercise in hot and humid environment are heat cramps, heat syncope, heat exhaustion, and heatstroke. Ways to prevent problems from heat illness include conditioning for the exercise, identifying the individuals who are most susceptible to heat problems, wearing proper clothing with as much skin as possible exposed to the air, evaluating the environmental conditions on the field, and providing adequate amounts of water on the field. Replacement of salt after practice through the use of electrolyte solutions and heavy salting of the food is important. However, the key to prevention of problems associated with environmental heat is to provide plenty of water before, during, and after the exercise.