Hyperthermia, << `hy` puhr THUR mee uh, >> is a condition that occurs when the body becomes overheated. Normally, when the temperature of the body increases, excess heat is released through the skin. Blood vessels near the skin dilate (widen) to bring warm blood to the surface. Heat then escapes and the body cools. The body is also cooled by the evaporation of sweat. When the body is unable to release heat in these ways, illness occurs. Hyperthermia differs from hypothermia, a condition in which body temperature is below normal (see Hypothermia).
People usually seek relief from extreme heat before they feel ill. At times, however, athletes and people who work outdoors may ignore the first signs of illness. Others commonly affected by hyperthermia include elderly people, children, and people with heart disease or other conditions that cause poor circulation.
Forms of hyperthermia.
The most common form of hyperthermia is heat exhaustion. It is caused by the loss of a large amount of fluid in the body as a result of excessive sweating. It typically strikes people who work for long periods in heat and humidity while wearing heavy clothing. Symptoms of heat exhaustion include headache, nausea, dizziness, and cool, moist, pale, or red skin. The condition is sometimes preceded by painful muscle spasms called heat cramps. Heat exhaustion can usually be relieved by immediate first-aid care. But if symptoms are ignored or no care is given, the condition may quickly worsen to a more serious form of hyperthermia called heatstroke.
Heatstroke is characterized by vomiting; red, hot, dry skin; rapid pulse; rapid, shallow breathing; and a progressive loss of consciousness. It develops when the body’s heat-regulating mechanism is disturbed and sweating stops. The body then cannot cool itself effectively and its temperature rises to a level at which the brain and other vital organs begin to fail. Convulsions, coma, and death may result if the body is not cooled. Heatstroke caused by the sun is commonly called sunstroke.
Treatment of hyperthermia
involves immediately cooling the body and replacing fluids. Move the victim to a cool environment and provide cool water to drink. Loosen tight clothing and remove perspiration-soaked clothing. Apply cool, wet cloths to the skin and fan the victim.
If the victim refuses water, vomits, or begins to lose consciousness, call for medical help immediately. Cool the victim by applying ice packs or cold compresses to the head, neck, and places where large blood vessels are near the skin. A person suffering heatstroke may experience a heart attack or breathing failure, requiring artificial respiration or cardiopulmonary resuscitation (CPR) to be given (see Cardiopulmonary resuscitation).
