Thermoregulation is a process that allows your body to maintain its core internal temperature. All thermoregulation mechanisms are designed to return your body to homeostasis. This is a state of equilibrium.
A healthy internal body temperature falls within a narrow window. The average person has a baseline temperature between 98°F (37°C) and 100°F (37.8°C). Your body has some flexibility with temperature. However, if you get to the extremes of body temperature, it can affect your body’s ability to function. For example, if your body temperature falls to 95°F (35°C) or lower, you have “hypothermia.” This condition can potentially lead to cardiac arrest, brain damage, or even death. If your body temperature rises as high as 107.6°F (42 °C), you can suffer brain damage or even death.
Many factors can affect your body’s temperature, such as spending time in cold or hot weather conditions.
Factors that can raise your internal temperature include:
Factors that can lower your internal temperature include:
- drug use
- alcohol use
- metabolic conditions, such as an under-functioning thyroid gland
Your hypothalamus is a section of your brain that controls thermoregulation. When it senses your internal temperature becoming too low or high, it sends signals to your muscles, organs, glands, and nervous system. They respond in a variety of ways to help return your temperature to normal.
When your internal temperature changes, sensors in your central nervous system (CNS) send messages to your hypothalamus. In response, it sends signals to various organs and systems in your body. They respond with a variety of mechanisms.
If your body needs to cool down, these mechanisms include:
- Sweating: Your sweat glands release sweat, which cools your skin as it evaporates. This helps lower your internal temperature.
- Vasodilatation: The blood vessels under your skin get wider. This increases blood flow to your skin where it is cooler — away from your warm inner body. This lets your body release heat through heat radiation.
If your body needs to warm up, these mechanisms include:
- Vasoconstriction: The blood vessels under your skin become narrower. This decreases blood flow to your skin, retaining heat near the warm inner body.
- Thermogenesis: Your body’s muscles, organs, and brain produce heat in a variety of ways. For example, muscles can produce heat by shivering.
- Hormonal thermogenesis: Your thyroid gland releases hormones to increase your metabolism. This increases the energy your body creates and the amount of heat it produces.
If your internal temperature drops or rises outside of the normal range, your body will take steps to adjust it. This process is known as thermoregulation. It can help you avoid or recover from potentially dangerous conditions, such as hypothermia.