# Body Temperature --- **Body temperature** is a [[vital signs]] that shows how hot or cold you are. All of our various [[protein|proteins]] that make our body function work optimally in a narrow range, so our body temperature is surprisingly consistent. Maintaining that range is an important aspect of [[homeostasis]], and there are several mechanisms that all work toward keeping this temperature in a healthy range—a process collectively known as [[thermoregulation]] and regulated largely by the [[hypothalamus]]. >[!science] Normal Values > A normal adult body temperature is **35.8-37.5** °C (or **96.4-99.5** °F) Living things produce heat. All of our [[metabolism|metabolic reactions]] produce a little bit of heat as a byproduct, which really adds up considering how *many* metabolic reactions take place all the time in our body. Just keeping the lights on is warming. Our [[basal metabolic rate]] determines just how warm—a higher BMR will produce more heat than a lower BMR. Additionally, [[exercise]] drastically increases our energy expenditure and heat production. There's a reason why we talk about a burn! Take into account these two main factors (BMR and activity/exercise), a lot of our thermoregulation involves making sure we don't get *too* hot. In fact, apparently our [[sweat glands|sweating]] adaptation, despite being resource (water) intensive, was one of the adaptations that put humans ahead of the [[evolution]] game. Some other things that affect our body temperature: - [[circadian rhythm]] - [[menstrual cycle]] - insulation/amount of [[adipose tissue]] ## Problems with Body Temp/Thermoregulation - A [[fever]] is a defense mechanism that our body uses in the case of an infection (or suspected infection) of a [[pathogen]]. The benefits of a fever are twofold: 1) most pathogens work optimally at the same temperature that our own bodies work at, so upping the temperature makes them work inefficiently, and 2) some of our immune cells actually work better at an elevated temperature, so they are even more efficient than normal. Unfortunately a sustained high fever can be quite damaging and even fatal, so doctors will monitor the fever and either let it "run it's course" or intervene, depending on the circumstance. - [[hypothermia]] is the opposite of a fever ___