$Unique_ID{BRK03848} $Pretitle{} $Title{Hyperthermia} $Subject{Hyperthermia Heat Stress Heat-Related Illness Malignant Hyperthermia Heat Exhaustion Heat Stroke } $Volume{} $Log{} Copyright (C) 1989 National Organization for Rare Disorders, Inc. 728: Hyperthermia ** IMPORTANT ** It is possible that the main title of the article (Hyperthermia) is not the name you expected. Please check the SYNONYM listing to find the alternate names and disorder subdivisions covered by this article. Synonyms Heat Stress Heat-Related Illness Information on the following diseases can be found in the Related Disorders section of this report: Malignant Hyperthermia Heat Exhaustion Heat Stroke General Discussion ** REMINDER ** The information contained in the Rare Disease Database is provided for educational purposes only. It should not be used for diagnostic or treatment purposes. If you wish to obtain more information about this disorder, please contact your personal physician and/or the agencies listed in the "Resources" section of this report. Hyperthermia, though not rare, can be a serious health condition. Left untreated it may become life-threatening. Hyperthermia occurs when the body is extremely overheated. It is most common in older persons during the summer months. Major symptoms include headache, nausea, and fatigue. Without treatment the body may be unable to return to the proper temperature of 98.6 F and heat exhaustion or heat stroke may occur. (See related disorder section for information on these conditions). Symptoms Hyperthermia occurs when an overheated body is unable to reduce body temperature to a normal 98.6 degrees F. This usually occurs during the heat of summer, but may be triggered by other health problems or certain medications. symptoms include headache, nausea, fatigue, muscle cramps, thirst and profuse sweating. The skin may feel cold and clammy. Without appropriate and prompt treatment to cool the body, Hyperthermia may progress to more complicated conditions. Causes Hyperthermia is caused by heat. Hot summer weather, being out in the sun for too long a period of time, excessive exercise in the heat, over extended stays in a hot tub or sauna, or being in an overcrowded or overheated room without adequate ventilation can cause Hyperthermia. Certain medications (particularly diuretics), alcoholic beverages, certain medical conditions and being overdressed in hot weather also causes Hyperthermia. The inability to perspire sufficiently, high blood pressure or poor blood circulation may play an important role in susceptibility to Hyperthermia. Affected Population Hyperthermia affects males and females in equal numbers. It is common in people over fifty years of age, those confined to nursing homes, and people with other medical problems. Younger, healthy persons are rarely affected. Infants can also be affected by the heat since they cannot communicate their needs to others. Related Disorders The following disorders may be associated with Hyperthermia. Malignant Hyperthermia is a genetic disorder characterized by an abnormal response to certain anesthesia drugs. The patient normally shows no symptoms of discomfort or illness in every day life. However anesthesia given for surgery, such as halothane or cyclopropane, or muscle relaxants such as succinylcholine, causes a life threatening high fever that can rise as high as 110 degrees F. Muscle rigidity and/or twitching may also occur. The patient may also exhibit a very rapid and irregular heartbeat, abnormally low blood pressure, sickly sweet breath, headache, nausea and vomiting. (For more information on this disorder, choose "Malignant Hyperthermia" as your search term in the Rare Disease Database). Heat Exhaustion is caused by dehydration and loss of mineral salts from the body due to heat stress usually of three or more days duration. It is often seen in the elderly who are unaware of excessive water loss or are unable to replenish lost fluids. Symptoms of heat exhaustion resulting from fluid loss include intense thirst, fatigue, weakness, anxiety, and impaired judgment. There may also be dehydration, rapid breathing (hyperventilation), and behavioral abnormalities. Elderly people taking diuretic drugs for hypertension are particularly prone to heat exhaustion. Heat Stroke is a life-threatening condition requiring immediate treatment. It occurs mainly in the poor, the elderly, the chronically ill, alcoholics and patients with heart disease. Hot, humid weather usually precedes this type of illness. Symptoms include a body temperature of 104 F or above, central nervous system dysfunction, confusion, bizarre behavior, faintness, and eventually coma. There may also be a rapid pulse, extreme drop in blood pressure, and hot, dry, flushed skin. Heat Stroke may be complicated by hemorrhage, jaundice, kidney failure, brain damage, peripheral neuropathy, or heart and lung damage. Survival depends on rapid reduction of body temperature usually in a hospital. Illness involving dysfunction of the sweat glands, can be found in the Rare Disease Database by typing "Hyperhidrosis" as your search term. Therapies: Standard Treatment of Hyperthermia consists of cooling the body. Cool showers, use of fans or air conditioners, drinking plenty of fluids (excluding those that contain caffeine or alcohol) helps maintain the correct body temperature. Cool, slightly salty fluids may help restore body salts lost during sweating. People prone to Hyperthermia should avoid being in the sun, wearing heavy clothing in hot, humid weather and staying out of overcrowded and under-ventilated environments. Therapies: Investigational This disease entry is based upon medical information available through January 1990. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder. Resources For more information on Hyperthermia, please contact: National Organization for Rare Disorders (NORD) P.O. Box 8923 New Fairfield, CT 06812-1783 (203) 746-6518 NIH/National Institute on Aging 9000 Rockville Pike Bethesda, MD 20892 (301) 496-1752 References CECIL TEXTBOOK OF MEDICINE, 18th Ed.: Wyngaarden and Smith, et al., eds.; W.B. Saunders, 1988, Pp. 1950, 2382-2385. HYPERTHERMIA A HOT WEATHER HAZARD FOR OLDER PEOPLE, U.S. Department of Health and Human Services, National Institute on Aging, U.S. Publication No. 89-2763, August, 1989.