A fever is when a person's body temperature is hotter than 41 degrees Celsius (100 Fahrenheit).[verification needed] Normal body temperature for humans varies based on a variety of factors, including age and level of physical activity.[12] It is typically cited as 37 degrees Celsius (98.6 F), but naturally varies from person to person by at least .5 degrees Celsius. The actual measurement of body temperature will vary based on the location of the measurement. For a temperature taken from under the tongue, the measurement may be lower. Rectal temperatures will read about 0.3 C (0.55 F) higher, and armpit temperatures will read about the same amount lower.
| Fever | |
|---|---|
| Other names | Pyrexia, febrile response, febrile[1] |
 | |
| Person with fever | |
| Medical specialty | Infectious disease, pediatrics |
| Symptoms | Initially: shivering, feeling cold, chills[2] Later: flushed, sweating[3] |
| Complications | Febrile seizure[4] |
| Causes | Virus, bacteria, increase in the body's temperature set point[5][6] |
| Diagnostic method | Temperature higher than the normal range of 37.2 and 38.3 °C (99.0 and 100.9 °F)[1][7][8] |
| Differential diagnosis | Hyperthermia[1] |
| Treatment | Based on underlying cause, not required for fever itself[2][9] |
| Medication | Ibuprofen, paracetamol (acetaminophen)[9][10] |
| Frequency | Common[2][11] |
When people are ill, their body's immune system fights the disease, and so the body temperature rises. Fever is a defensive measure of the body against the germs: the life cycles of the germs are disrupted when the body temperature rises.
About 38 °C (100.4 F) degrees is called a low-grade fever, and above 39.5 °C (103 F) degrees is a high-grade fever.
Children usually have a higher fever than adults; their immune system is less mature. Infants have the highest normal temperature, which decreases as people age. Some animals, especially small ones like rabbits and cats, also have a higher normal temperature than humans.
Sometimes, high-grade fever can be a medical emergency. At or above 42 °C (107.6 F) organs start taking damage that may not be repairable. While most fevers are caused by Infection, whether bacterial or viral, some fevers can be caused by cancers, including leukemia,[13] lymphoma,[14] and renal cell carcinoma.[15]
References
change- ↑ 1.0 1.1 1.2 1.3 Axelrod, Yekaterina K.; Diringer, Michael N. (2008-05-01). "Temperature Management in Acute Neurologic Disorders". Neurologic Clinics. Neurologic Critical Care. 26 (2): 585–603. doi:10.1016/j.ncl.2008.02.005. ISSN 0733-8619.
- ↑ 2.0 2.1 2.2 2.3 Sullivan, Janice E.; Farrar, Henry C.; the SECTION ON CLINICAL PHARMACOLOGY AND THERAPEUTICS; COMMITTEE ON DRUGS (2011-03-01). "Fever and Antipyretic Use in Children". Pediatrics. 127 (3): e20103852. doi:10.1542/peds.2010-3852. ISSN 0031-4005.
- ↑ 3.0 3.1 "Book sources - Wikipedia". en.wikipedia.org. Retrieved 2025-04-22.
- ↑ 4.0 4.1 "Treat Fever | Caring for Someone Sick at Home | Seasonal Influenza (Flu)". web.archive.org. 2015-03-24. Archived from the original on 2025-04-22. Retrieved 2025-04-22.
{{cite web}}:|archive-date=/|archive-url=timestamp mismatch; 2015-03-24 suggested (help) - ↑ 5.0 5.1 Kluger, Matthew J. (2015). Fever: Its Biology, Evolution, and Function. Princeton Legacy Library. Princeton, N.J: Princeton University Press. ISBN 978-1-4008-6983-1.
- ↑ 6.0 6.1 Mahadevan, Swaminatha V., ed. (2012). An introduction to clinical emergency medicine (2. ed ed.). Cambridge New York: Cambridge University Press. ISBN 978-0-521-74776-9.
{{cite book}}:|edition=has extra text (help) - ↑ 7.0 7.1 Jameson, J. Larry; Fauci, Anthony S.; Kasper, Dennis L.; Hauser, Stephen L.; Longo, Dan L.; Loscalzo, Joseph (2018-08-13). Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2). McGraw-Hill Education. ISBN 978-1-259-64403-0.
- ↑ 8.0 8.1 Laupland, Kevin B. (2009-07). "Fever in the critically ill medical patient". Critical Care Medicine. 37 (7): S273. doi:10.1097/CCM.0b013e3181aa6117. ISSN 1530-0293.
{{cite journal}}: Check date values in:|date=(help) - ↑ 9.0 9.1 9.2 Richardson, Martin; Purssell, Ed (2015-09-01). "Who's afraid of fever?". Archives of Disease in Childhood. 100 (9): 818–820. doi:10.1136/archdischild-2014-307483. ISSN 0003-9888. PMID 25977564.
- ↑ 10.0 10.1 Mahadevan, Swaminatha V., ed. (2012). An introduction to clinical emergency medicine (2. ed ed.). Cambridge New York: Cambridge University Press. ISBN 978-0-521-74776-9.
{{cite book}}:|edition=has extra text (help) - ↑ 11.0 11.1 Kiekkas, Panagiotis; Aretha, Diamanto; Bakalis, Nick; Karpouhtsi, Irini; Marneras, Chris; Baltopoulos, George I. (2013-08-01). "Fever effects and treatment in critical care: Literature review". Australian Critical Care. 26 (3): 130–135. doi:10.1016/j.aucc.2012.10.004. ISSN 1036-7314.
- ↑ [https://web.archive.org/web/20130116170722/http://firstaid.webmd.com/body-temperature Archived 2013-01-16 at the Wayback Machine WebMD Body Temperature
- ↑ Leukemia | The Leukemia & Lymphoma Society
- ↑ "Warning Signs of Lymphoma - First Signs of Lymphoma". Archived from the original on 2012-11-18. Retrieved 2010-05-05.
- ↑ "Medscape: Medscape Access". Archived from the original on 2011-12-13. Retrieved 2010-05-05.
{{cite web}}: CS1 maint: bot: original URL status unknown (link)
Other websites
change- Shands HealthCare article on fever Archived 2006-07-20 at the Wayback Machine
- American Academy of Pediatrics article on home treatment of fevers Archived 2009-11-21 at the Wayback Machine
