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It is possible that the main title of the report Hyperthermia is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.


  • Heat Stress
  • Heat-Related Illness

Disorder Subdivisions

  • None

General Discussion

Hyperthermia occurs when a person's body temperature rises and remains above the normal; 98.6°F Most frequently, this occurs during the heat of summer and among the elderly. However, it may also be triggered by other medical conditions or certain medications.

Hyperthermia is sometimes induced as a palliative measure in the treatment of certain cancerous conditions.


Symptoms of hyperthermia include headache, nausea, fatigue, muscle cramps, thirst and profuse sweating, notwithstanding that the skin may feel cold and clammy. Without appropriate and prompt treatment to cool the body, hyperthermia may progress to more complicated and more dangerous conditions.


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 Populations

Hyperthermia affects males and females in equal numbers. It is common in people over 50 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.

Standard Therapies

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.

Investigational Therapies

Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. government funding, and some supported by private industry, are posted on this government web site.

For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:

Tollfree: (800) 411-1222

TTY: (866) 411-1010

Email: prpl@cc.nih.gov

For information about clinical trials sponsored by private sources, contact:




Yoder E., Disorders due to heat and cold. In: Bennett JC, Plum F, eds. Cecil Textbook of Medicine. 20th ed. Philadelphia, PA; W.B. Saunders Company. 1996;501-2.

Dale DC, The febrile patient. In: Bennett JC, Plum F, eds. Cecil Textbook of Medicine. 20th ed. Philadelphia, PA; W.B. Saunders Company. 1996;1532.

Beutler B, Beutler SM, The pathogenesis of fever. In: Bennett JC, Plum F, eds. Cecil Textbook of Medicine. 20th ed. Philadelphia, PA; W.B. Saunders Company. 1996;1533.


Prentice HG, et al., Liposomal amphotericin B for fever and neutropenia. N Engl J Med. 1999;341:1152-53.

Rakita R, Liposomal amphotericin B for fever and neutropenia. N Engl J Med. 1999;341:1153-54.


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For a Complete Report

This is an abstract of a report from the National Organization for Rare Disorders, Inc.® (NORD). Cigna members can access the complete report by logging into myCigna.com. For non-Cigna members, a copy of the complete report can be obtained for a small fee by visiting the NORD website. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational treatments (if available), and references from medical literature. For a full-text version of this topic, see http://www.rarediseases.org/search/rdblist.html.