Fever
A fever is when a person's body temperature is hotter than 38 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 | |
| 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]
Fever Media
Different fever patterns observed in Plasmodium infections
Plate 11: Febris (?); WL figure, frontal view, the head in profile to r; surrounded by floating drapery; from a series of twelve engravings of mythological women in elaborate strapwork borders. Etching and engraving*Inscription type: inscription Inscription content: Signed with monogram 'V/S' at lower centre. Numbered 11 above the figure and lettered 'FE/B' to the right.
References
- ↑ 1.0 1.1 1.2 1.3 Axelrod, Yekaterina K.. Temperature Management in Acute Neurologic Disorders. Neurologic Critical Care. Neurologic Clinics 26 (2) (2008-05-01). p. 585–603. doi:10.1016/j.ncl.2008.02.005.
- ↑ 2.0 2.1 2.2 2.3 Sullivan, Janice E.. Fever and Antipyretic Use in Children. Pediatrics 127 (3) (2011-03-01). p. e20103852. doi:10.1542/peds.2010-3852.
- ↑ 3.0 3.1 Book sources - Wikipedia (in en). en.wikipedia.org. Retrieved 2025-04-22.
- ↑ 4.0 4.1 Treat Fever | Caring for Someone Sick at Home | Seasonal Influenza (Flu) (2015-03-24). Retrieved 2025-04-22.
- ↑ 5.0 5.1 Kluger, Matthew J.. Fever: Its Biology, Evolution, and Function. Princeton Legacy Library (2015). Princeton, N.J: Princeton University Press. ISBN 978-1-4008-6983-1.
- ↑ 6.0 6.1 An introduction to clinical emergency medicine (2012). Cambridge New York: Cambridge University Press. ISBN 978-0-521-74776-9.
- ↑ 7.0 7.1 Jameson, J. Larry. Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2) (in en) (2018-08-13)McGraw-Hill Education. ISBN 978-1-259-64403-0.
- ↑ 8.0 8.1 Laupland, Kevin B.. Fever in the critically ill medical patient (in en-US). Critical Care Medicine 37 (7) (July 2009). p. S273–S278. doi:10.1097/CCM.0b013e3181aa6117.
- ↑ 9.0 9.1 9.2 Richardson, Martin. Who's afraid of fever? (in en). Archives of Disease in Childhood 100 (9) (2015-09-01). p. 818–820. doi:10.1136/archdischild-2014-307483.
- ↑ 10.0 10.1 An introduction to clinical emergency medicine (2012). Cambridge New York: Cambridge University Press. ISBN 978-0-521-74776-9.
- ↑ 11.0 11.1 Kiekkas, Panagiotis. Fever effects and treatment in critical care: Literature review (in English). Australian Critical Care 26 (3) (2013-08-01). p. 130–135. doi:10.1016/j.aucc.2012.10.004.
- ↑ [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. Retrieved 2010-05-05.
- ↑ Medscape: Medscape Access. Retrieved 2010-05-05.
Other websites
- 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