BODY TEMPERATURE DURING AND AFTER EXERCISE IN HOT, HUMID WEATHER
It is important to note that the post workout time period is when you need to provide some assistance and help the body in its cooling effort. As Gabe Mirkin, M.D. (http://www.DrMirkin.com) points out, you sweat more after exercise than while exercising. Body temperature also continues to rise, adding to the over heated condition. During exercise, about 70 percent of the energy that powers muscles is lost as heat, causing body temperature to rise. To prevent temperature from rising too high, the heart pumps the heat in the blood from muscles to the skin, increasing perspiration and the efficiency of the body’s main cooling mechanism; evaporation of sweat.
The amount of perspiration is controlled by the temperature of the blood flowing to the part of the brain called the hypothalamus. When body temperature rises, additional sweating occurs. During exercise, the heart beats rapidly to pump blood and bring oxygen to muscles and hot blood from the muscles to the skin where the heat can be dissipated. When exercise stops, the heart slows down, the amount of blood pumped to your skin decreases, the amount of sweat increases, and temperature rises. At this point you can help by getting out of the sun, entering an air conditioned or cool area, drinking cold water and cold electrolyte drinks, and applying cool towels to the elbows, back of the knee, and neck areas.
Body temperatures commonly reach 101 F during workouts in a warm gym or weight room. At the extreme, marathon runners may finish the race with temperatures considerably higher. One such runner supposedly developed a temperature of over 107 F. With a temperature of 102 F+ muscle discomfort occurs that may produce a burning sensation, over 104 F results in shortness o fbreath, and with temperatures over 105 F brain distress occurs (headache, blurred vision, ringing in the ears, dizziness, nausea, and possibly unconsciousness).
The higher the temperature, the more difficult it becomes to dissipate heat and cool the body. The key to protecting yourself from heat stroke is to avoid acquiring unusually high core temperatures by drinking fluids and electrolyte solutions freely prior to exercise or competition (loading), drinking freely during the activity session, drinking before you are thirsty, wearing a visor type hat to allow the heat to dissipate through the head, changing wet clothing frequently, and using shade to protect yourself from the sun whenever possible.