Human body temperature

Temperature classification
Core (rectal, esophageal, etc.)
Hypothermia <35.0 °C (95.0 °F)[1]
Normal 36.5–37.5 °C (97.7–99.5 °F)[2][3]
Fever >37.5 or 38.3 °C (99.5 or 100.9 °F)[4][5]
Hyperthermia >37.5 or 38.3 °C (99.5 or 100.9 °F)[4][5]
Hyperpyrexia >40.0 or 41.0 °C (104.0 or 105.8 °F)[6][7]
Note: The difference between fever and hyperthermia is the underlying mechanism. Different sources have different cut-offs for fever, hyperthermia and hyperpyrexia.

Normal human body temperature (normothermia, euthermia) is the typical temperature range found in humans. The normal human body temperature range is typically stated as 36.5–37.5 °C (97.7–99.5 °F).[8][9]

Human body temperature varies. It depends on sex, age, time of day, exertion level, health status (such as illness and menstruation), what part of the body the measurement is taken at, state of consciousness (waking, sleeping, sedated), and emotions. Body temperature is kept in the normal range by a homeostatic function known as thermoregulation, in which adjustment of temperature is triggered by the central nervous system.

  1. ^ Marx J (2006). Rosen's emergency medicine : concepts and clinical practice (6th ed.). Philadelphia: Mosby/Elsevier. p. 2239. ISBN 978-0-323-02845-5. OCLC 58533794.
  2. ^ Hutchison JS, Ward RE, Lacroix J, Hébert PC, Barnes MA, Bohn DJ, et al. (June 2008). "Hypothermia therapy after traumatic brain injury in children". The New England Journal of Medicine. 358 (23): 2447–56. doi:10.1056/NEJMoa0706930. PMID 18525042.
  3. ^ Pryor JA, Prasad AS (2008). Physiotherapy for Respiratory and Cardiac Problems: Adults and Paediatrics. Elsevier Health Sciences. p. 8. ISBN 978-0702039744. Body temperature is maintained within the range 36.5-37.5 °C. It is lowest in the early morning and highest in the afternoon.
  4. ^ a b Axelrod YK, Diringer MN (May 2008). "Temperature management in acute neurologic disorders". Neurologic Clinics. 26 (2): 585–603, xi. doi:10.1016/j.ncl.2008.02.005. PMID 18514828.
  5. ^ a b Laupland KB (July 2009). "Fever in the critically ill medical patient". Critical Care Medicine. 37 (7 Suppl): S273-8. doi:10.1097/CCM.0b013e3181aa6117. PMID 19535958.
  6. ^ Grunau BE, Wiens MO, Brubacher JR (September 2010). "Dantrolene in the treatment of MDMA-related hyperpyrexia: a systematic review". Cjem. 12 (5): 435–42. doi:10.1017/s1481803500012598. PMID 20880437. Dantrolene may also be associated with improved survival and reduced complications, especially in patients with extreme (≥ 42 °C) or severe (≥ 40 °C) hyperpyrexia
  7. ^ Sharma HS, ed. (2007). Neurobiology of Hyperthermia (1st ed.). Elsevier. pp. 175–177, 485. ISBN 9780080549996. Retrieved 19 November 2016. Despite the myriad of complications associated with heat illness, an elevation of core temperature above 41.0 °C (often referred to as fever or hyperpyrexia) is the most widely recognized symptom of this syndrome.
  8. ^ Cite error: The named reference Kar2008 was invoked but never defined (see the help page).
  9. ^ Ley, C; Heath, F; Hastie, T; Gao, Z; Protsiv, M; Parsonnet, J (5 September 2023). "Defining usual oral temperature ranges in outpatients using an unsupervised learning algorithm". JAMA Internal Medicine. 183 (10): 1128–1135. doi:10.1001/jamainternmed.2023.4291. PMC 10481327. PMID 37669046.