Hyperthermia

Hyperthermia
Other namesOverheating
An analog medical thermometer showing a temperature of 38.7 °C (101.7 °F)
SpecialtyCritical care medicine
SymptomsLack of perspiration, confusion, delirium, decreased blood pressure, increased heart rate and respiration rate, symptoms of dehydration
ComplicationsOrgan failure, unconsciousness
CausesHeat stroke[1]
Risk factorsExposure to hot and/or humid environments, physical exertion, wearing personal protective equipment that covers the body, heatwaves
Diagnostic methodBased on symptoms or body temperature above 37.7 °C (99.9 °F)[2]
Differential diagnosisFever[3]
PreventionMaintaining a moderate temperature, regular hydration, taking regular breaks
TreatmentMild: Staying away from hot environments, rehydrating oneself, mechanical cooling, use of a dehumidifier
Severe: intravenous hydration, gastric lavage with iced saline, hemodialysis, immersing in ice water

Hyperthermia, also known simply as overheating, is a condition in which an individual's body temperature is elevated beyond normal due to failed thermoregulation. The person's body produces or absorbs more heat than it dissipates. When extreme temperature elevation occurs, it becomes a medical emergency requiring immediate treatment to prevent disability or death.[citation needed] Almost half a million deaths are recorded every year from hyperthermia.[citation needed]

The most common causes include heat stroke and adverse reactions to drugs. Heat stroke is an acute temperature elevation caused by exposure to excessive heat, or combination of heat and humidity, that overwhelms the heat-regulating mechanisms of the body. The latter is a relatively rare side effect of many drugs, particularly those that affect the central nervous system. Malignant hyperthermia is a rare complication of some types of general anesthesia. Hyperthermia can also be caused by a traumatic brain injury.[4][5][6]

Hyperthermia differs from fever in that the body's temperature set point remains unchanged. The opposite is hypothermia, which occurs when the temperature drops below that required to maintain normal metabolism. The term is from Greek ὑπέρ, hyper, meaning "above", and θέρμος, thermos, meaning "heat".

  1. ^ Bouchama, Abderrezak; Knochel, James P. (20 June 2002). "Heat Stroke". New England Journal of Medicine. 346 (25): 1978–1988. doi:10.1056/nejmra011089. ISSN 0028-4793. PMID 12075060.
  2. ^ Cite error: The named reference Harrisons was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference NC08 was invoked but never defined (see the help page).
  4. ^ Thompson, Hilaire J.; Tkacs, Nancy C.; Saatman, Kathryn E.; Raghupathi, Ramesh; McIntosh, Tracy K. (April 2003). "Hyperthermia following traumatic brain injury: a critical evaluation". Neurobiology of Disease. 12 (3): 163–173. doi:10.1016/s0969-9961(02)00030-x. ISSN 0969-9961. PMID 12742737. S2CID 23680754.
  5. ^ Truettner, Jessie S.; Bramlett, Helen M.; Dietrich, W. Dalton (1 April 2018). "Hyperthermia and Mild Traumatic Brain Injury: Effects on Inflammation and the Cerebral Vasculature". Journal of Neurotrauma. 35 (7): 940–952. doi:10.1089/neu.2017.5303. ISSN 0897-7151. PMC 5865622. PMID 29108477.
  6. ^ Thompson, H. J.; Pinto-Martin, J.; Bullock, M. R. (1 May 2003). "Neurogenic fever after traumatic brain injury: an epidemiological study". Journal of Neurology, Neurosurgery & Psychiatry. 74 (5): 614–619. doi:10.1136/jnnp.74.5.614. ISSN 0022-3050. PMC 1738450. PMID 12700304.