Maintaining proper body temperature is part of a good immune system, auto immune system and everything else that has to do with being a functioning entity. People are only meant to exist within a certain range of temperatures - above and below that they get sick and die. One of the worst things for the human body is heat and humidity.

Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different.

A thermoconforming organism, by contrast, simply adopts the surrounding temperature as its own body temperature, thus avoiding the need for internal thermoregulation.

The internal thermoregulation process is one aspect of homeostasis: a state of dynamic stability in an organism's internal conditions, maintained far from thermal equilibrium with its environment (the study of such processes in zoology has been called physiological ecology).

If the body is unable to maintain a normal temperature and it increases significantly above normal, a condition known as hyperthermia occurs. Humans may also experience lethal hyperthermia when the wet bulb temperature is sustained above 35°C (95°F) for six hours.

The opposite condition, when body temperature decreases below normal levels, is known as hypothermia. It results when the homeostatic control mechanisms of heat within the body malfunction, causing the body to lose heat faster than producing it. Normal body temperature is around 37°C (99°F), and hypothermia sets in when the core body temperature gets lower than 35°C (95°F).

Usually caused by prolonged exposure to cold temperatures, hypothermia is usually treated by methods that attempt to raise the body temperature back to a normal range.

It was not until the introduction of thermometers that any exact data on the temperature of animals could be obtained. It was then found that local differences were present, since heat production and heat loss vary considerably in different parts of the body, although the circulation of the blood tends to bring about a mean temperature of the internal parts.

Hence it is important to identify the parts of the body that most closely reflect the temperature of the internal organs. Also, for such results to be comparable, the measurements must be conducted under comparable conditions. The rectum has traditionally been considered to reflect most accurately the temperature of internal parts, or in some cases of sex or species, the vagina, uterus or bladder.

Some animals undergo one of various forms of dormancy where the thermoregulation process temporarily allows the body temperature to drop, thereby conserving energy. Examples include hibernating bears and torpor in bats. Continue reading

Study identifies key neurons that maintain normal body temperature in mammals   Medical Express - December 23, 2022

A research group at Nagoya University in Japan has reported that a group of neurons, called EP3 neurons, in the preoptic area of the brain play a key role in regulating body temperature in mammals. The finding could pave the way for the development of a technology that artificially adjusts body temperature to help treat heat stroke, hypothermia, and even obesity.

Body temperature in humans and many other mammals is regulated at about 37°C (98.6°F), which optimizes all regulatory functions. When body temperature noticeably deviates from the normal range, functions are impaired, which could lead to heat stroke, hypothermia, and, in the worst case, death. However, these conditions might be treated if body temperature can be artificially adjusted to the normal range.

The brain's temperature regulation center resides in the preoptic area, a part of the hypothalamus that controls the body's vital functions. For example, when the preoptic area receives signals from a mediator called prostaglandin E (PGE2) that is produced in response to infections, this area releases a command to raise body temperature to fight against viruses, bacteria, and other disease-causing organisms. However, it is still unclear exactly which neurons in the preoptic area release commands to increase or decrease body temperature.