According to the University of New Mexico (UNM), the human body maintains temperature by keeping a strict balance between heat loss and heat gain. The hypothalamus, which is found in the brain, is considered the body’s thermostat, as it regulates the core temperature. It responds to different temperature receptors in the body and makes necessary physiological adjustments to maintain a constant core temperature.
Humans regulate the generation and preservation of heat in order to maintain internal body temperature, which is also called core temperature. Normal core temperature at rest lies around 98.6 degrees Fahrenheit. The hypothalamus triggers changes to effectors, such as sweat glands and muscles that control body hair. When the weather is hot, temperature receptors in the skin send signals to the hypothalamus, causing an increase in sweat to cool the body.
BBC explains that the skin has temperature receptors that detect changes in external temperature. There are also receptors that detect temperature changes of the blood. Information on external temperatures is passed on to the hypothalamus, which immediately makes changes to the effectors to maintain a constant body temperature.
According to Hyperphysics, the hypothalamus initiates various responses when the skin temperature drops below 98.6 degrees Fahrenheit. The body ceases sweating, performs vasoconstriction to decrease the heat flow to the skin, secrets thyroxine, epinephrine and norepinephrine to boost heat production and shivers to increase production of heat in the muscles.