The human body has its own heating and cooling system that works constantly to keep itself at a constant temperature. Called the hypothalamus, this cone-shaped gland is located in the brain and is responsible for controlling the temperature of the body. The hypothalamus stimulates muscles that control body hair to help the human body stay warm and it triggers the sweat glands to cool the body.
The human body’s internal temperature
The human body keeps a consistent internal temperature of 37C or 98.6F. The hypothalamus regulates the temperature by ensuring the heat a body generates is equal to the heat that is lost. The human body generates heat even when it is not moving. Blood, circulating through the body, keeps our body warm. It is important to note it is possible for our limbs and hands and feet to be cooler than our internal body temperature. This is due to factors such as external temperature and to the amount of energy spent by the blood as it moves within the body.
The hypothalamus has the important job of keeping the internal organs of the body at a steady temperature. While the extremities and limbs can lose heat or gain heat in small amounts without much danger, the organs of the body need to be maintained at a constant temperature.
Much like a thermostat senses changes in temperature, the human body has tiny receptors built into the skin that sense change in the temperature on the outside the body. This information is passed to the hypothalamus, or main temperature control of the body. There are also receptors built into the body that notify the hypothalamus if the temperature of the blood changes.
What happens when temperature changes within the body
If the sensors notify the hypothalamus that the external temperature surrounding the body has changed or the internal temperature of the body has risen or dropped past 37C or 98.6F, the hypothalamus works to regulate the temperature.
If the human body is in danger of becoming too cold, the hypothalamus causes the muscles in the body to contract to help the body warm. These muscle contractions are known as shivering, and the movement is designed to put heat back into the body. It also causes the hair on the arms to stand up, which warms the human body. These movements are designed to protect the body and the organs within. If the body gets too cold, hypothermia sets in. This occurs when the temperature of the human body drops below 35C or 95F, because the human body is losing heat faster than it can manufacture it.
If the human body begins to get too warm, the hypothalamus reacts by stimulating the skin and the sweat glands. The sweat glands secrete fluid known as sweat onto the skin. The sweat serves to cause the body to lose heat through the evaporation process. If the external temperature rises too rapidly and the body cannot keep up through the sweating process, heat exhaustion and heat stroke can take place. That is why it is vital the human body remains hydrated when outside or when external temperatures are hot.
The hypothalamus also works on the blood vessels, causing them to expand if the human body becomes too hot and to contract if the human body becomes too cold. When the blood vessels expand, blood is pushed closer to the surface of the skin causing the body to flush or appear red. When the blood vessels constrict, blood is drawn away from the skin in an effort to heat the blood, causing the skin to whiten or to appear pale.
It is amazing to consider one small gland located within the brain controls the temperature for the entire human body.