Britannica
Sources used in this answer
How do sweating and vasodilation lower body temperature?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
Thermoreception
Warm-blooded animals, such as polar bears, maintain stable body temperatures and adapt to substantial geographic and seasonal temperature fluctuations. Thermal adaptation is supported by the function of sensory structures called thermoreceptors.
Sweating and vasodilation are key physiological mechanisms used by the body to dissipate heat and maintain a stable internal temperature, a process regulated by the hypothalamus.123
- Sweating: When the body temperature rises, the nervous system stimulates sweat glands to secrete water onto the skin surface. As this liquid evaporates, it absorbs heat from the body, effectively cooling the surface and lowering overall body temperature.14
- Vasodilation: The hypothalamus controls the diameter of blood vessels in the skin. During vasodilation, these vessels widen, which increases the flow of warm blood from the body's core to the skin surface. This allows heat to be more easily released into the external environment.123
Together, these autonomic responses function like a thermostat to ensure the body remains within its optimal temperature range.12