Heat injury, or hyperthermia, occurs when these mechanisms fail to restore normal body temperature. Heat injury can take the form of heat cramps, heat exhaustion and heat stroke. Heat cramps are the mildest form of hyperthermia. A person with heat cramps may complain of muscle twitching, cramps or spasm. Treatment typically consists of drinking water to restore adequate hydration and rest in a cool environment.
Heat exhaustion is the next severe form of heat injury.
A person may complain of headache, fatigue, weakness, lack of coordination and excessive thirst as well as the symptoms of heat cramps. In addition, he or she may suffer nausea or diarrhea. He or she may have problems thinking and concentrating, weight loss, dry mouth, an elevated body temperature, and may appear ashen, cold and clammy. Treatment consists of moving the person to a cool place, sponging the skin with cool water, fanning and encouraging the consumption of cool liquids. If the person cannot drink, intravenous fluids are necessary.