What mechanism do the skin and sweat glands use to cool the body?

The skin and sweat glands primarily cool the body through the process of evaporation of sweat from the skin surface. When the body's temperature rises, whether due to external heat or physical activity, sweat glands become activated and produce sweat, which is composed mostly of water.

As this sweat accumulates on the skin, it absorbs heat from the body in order to change from a liquid state to a gas. This phase transition requires energy, which is taken from the body in the form of heat, resulting in a cooling effect. This process is particularly effective because it can significantly lower skin temperature, helping to regulate overall body temperature.

While conduction of heat to surrounding air, increased blood flow to the skin, and air circulation do play roles in thermoregulation, they are not as direct and effective as evaporation in cooling the body in response to heat and exertion. Evaporation is the primary mechanism due to its efficiency and the amount of heat it can remove from the body in a short time frame.