Heat illnesses are common problems for both athletes and non-athletes in hot, humid weather. Heat Cramps, Heat Exhaustion, and Heat Stroke start from similar circumstances: poor adjustment to hot weather and relative dehydration. These conditions can be severe and need emergency medical attention. All are preventable if certain procedures, such as time to adjust to heat, adequate fluids, and normal dietary electrolyte intake, are followed.

Heat Cramps
Cause
Inadequate adjustment to hot weather, heavy sweating; decreased blood levels of electrolytes; fluids and electrolytes not adequately replaced; unreplaced weight loss from previous workout/day.

Clinical signs and symptoms
Muscles in arms, legs, and/or abdomen spasm uncontrollably, accompanied by heavy sweating.

Treatment
Drink fluids; gently stretch and massage cramped muscles; rest in cool environment; apply ice to cramped area; watch for breathing or heart problems.

Prevention
Maintain adequate fluid intake by replacing sweat losses: 15-30 minutes before exercise, drink 16 oz. of fluid; during exercise, drink 8oz. every 15 minutes; and after exercise drink 16 oz. of water/electrolyte drink (i.e., PowerAde, Gatorade) for every pound of body weight loss; increase fitness; wear light colored and/or lightweight (i.e. mesh) clothing; do not use alcohol, coffee, caffienated drinks, or soda pop for fluid replacement.

Heat Exhaustion
Cause
Long exposure to hot and/or humid environment; heavy sweating; fluids and electrolytes not replaced adequately; unreplaced weight loss from previous workout/day.

Clinical signs and symptoms
Skin cool, pale and moist; heavy sweating; headache; dizziness; poor coordination; mental dullness; enlarged pupils; nausea; vomiting; fatigue; weakness; thirsty; small urine volume (bright yellow color); possibility of unconsciousness.

Treatment
Stop activity; rest in a cool area; sponge with cool water; drink water if conscious (replace weight loss with 16 oz of fluid for each pound of body weight); watch for breathing or heart problems; refer to physician attention if recovery does not occur quickly.

Prevention
Maintain adequate fluid intake by replacing sweat losses; 15-30 minutes before exercise drink 16 ounces of fluid, during exercise drink 8 ounces every 15 minutes, and after exercise drink 16 ounces of water-electrolyte drink (i.e. Powerade, Gatorade for every pound of body weight lost; increase fitness; wear light colored and/or lightweight (i.e. mesh) clothing; do not use alcohol, coffee, caffeinated drinks, or soda pop for fluid replacement; allow time for rest and cool down.

Heatstroke
Cause
Body's temperature control system stops working.

Clinical signs and symptoms
Hot, dry and red skin; no sweating; rapid pulse; confusion; dizziness; unconsciousness; rectal temperature as high as 104°-106° Fahrenheit.

Treatment: Medical Emergency!
Immediate emergency cooling (e.g. cool room, put body in tub of ice water, ice cloths with a fan blowing on skin) and transport immediately to hospital; check temperature; watch for breathing or heart problems (may need CPR)

Prevention
Maintain adequate fluid intake by replacing sweat losses; 15-30 minutes before exercise drink 16 ounces of fluid, during exercise drink 8 ounces every 15 minutes, and after exercise drink 16 ounces of water/electrolyte drink (i.e. mesh) clothing; do not use alcohol, coffee, caffeinated drinks, or soda pop for fluid replacement; allow time for rest and cool down.

(Thanks to Mark Stein, ATC, for his help with this project.)
1991 United States Olympic Committee (revised November 1999)