According to the American Red Cross: "Heat cramps, heat exhaustion and heat stroke are conditions caused by overexposure to heat. Heat crams are the least severe but, if not care for, may be followed by heat exhaustion and heat stroke. Heat Cramps Heat cramps are painful spasms of skeletal muscles. Heat cramps usually affect the legs and the abdomen but they can occur in any voluntary muscle. The exact cause of heat cramps is not known, although it is believed to be a combination of loss of fuluid and salt from heavy sweating. Heat cramsp develop fairly rapidly and usually occur after heavy exercise or work in warm or even moderate temperatures. The victim's body temperature is usually normal and skin moist. However, heat cramps may also indicate that a person is in early stages of a more severe heat-related emergency. To care for heat cramps, have the victim rest comfortably in a cool place. Lightly stretch the muscle, then grasp it firmly and squeeze it. Provide coll water or a commercial sports drink that contains nutrients, such as carbohydrates, electrolytes and simple sugars, to replace those lost through heavy sweating. Usually, rest and fluids are all the body needs to recover. The victim should not take salt tablets or salt walter. Ingesting high concentrations of salt, whether in tablt or liquid form, can hasten the onset of heat-related illness. Fresh water has enough disolved salts to replace the salt that was lost. When the cramsp stop and no other signals of illness are present, the person can usually resume activity. The person should be watched carefully, however, for signals of developing heat-related illness. He or she should continue to rink plenty of fluids during and after activity."