A condition in which the body temperature is higher than the normal range
Hyperthermia pertains to a condition in which the body temperature is higher than the normal range. In humans, the body temperature that is regarded as normal is around 37 °C or 98.6 °F (measured by an oral thermometer). Body temperature that is higher than that range is considered hypothermia. Essentially, the hypothalamus regulates the body temperature such that when the surroundings is too hot it tells the body to dissipate the heat, especially when the body absorbs more heat than it dissipates. When the heat-regulatory mechanisms of the body fail to do so the body temperature raises and exceeds the normal. In certain literature, the trigger of hyperthermia is limited to an external source, particularly the heat coming from the environment.1, 2 In other literature, hyperthermia is also regarded to be triggered by an internal factor such as when the immune system fights off an infection. Thus, it is used sometimes as a synonym for hyperpyrexia.
Word origin: Greek huper (over) + Greek therme (heat)
1 Axelrod YK, Diringer MN (May 2008). "Temperature management in acute neurologic disorders". Neurol. Clin. 26 (2): 585–603, xi.
2 Laupland KB (July 2009). "Fever in the critically ill medical patient". Crit. Care Med. 37 (7 Suppl): S273–8.
3 The Editors of Encyclopædia Britannica. 2014. Fever. Britannica.com. Retrieved from http://www.britannica.com/EBchecked/topic/205674/fever