Thermoregulation refers to how the body maintains its internal temperature. If your body temperature becomes too cold or hot, it may lead to severe symptoms and even death.

Thermoregulation is a process that allows your body to maintain its core internal temperature. All thermoregulation mechanisms help return your body to homeostasis. This is a state of equilibrium.

A typical 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, getting to the extremes of body temperature can affect your body’s ability to function.

For example, if your body temperature falls lower than 96°F (35°C) or lower, you have hypothermia. This condition can lead to cardiac arrest, brain damage, or even death.

You can experience heat stroke if your body temperature rises above 104°F (40°C). Heat stroke is considered a medical emergency. If your body temperature rises to high, you can experience brain damage or even death.

Many factors can affect your body’s temperature, such as spending time in cold or hot weather.

Factors that can raise your internal temperature include:

  • fever
  • exercise
  • digestion

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 the hypothalamus senses your internal temperature becoming too low or high, it sends signals to your muscles, organs, glands, and nervous system. They respond in various ways to help return your temperature to its typical levels.

When your internal temperature changes, sensors in your central nervous system 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 various 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 typical 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 like hypothermia.