How does the body primarily release heat?

The primary method by which the body releases heat is through varying blood circulation. Blood circulation plays a vital role in thermoregulation; when the body temperature rises, blood vessels near the surface of the skin dilate (a process called vasodilation). This increases blood flow to the skin, allowing heat to dissipate into the environment more effectively. By adjusting the amount of blood circulating near the skin's surface, the body can either release heat or retain it, depending on the external temperature and internal metabolic processes.

While sweating and evaporation do contribute to heat loss, they are typically considered secondary mechanisms. Sweat evaporates from the skin, providing a cooling effect, but this process is dependent on the body's ability to regulate blood flow. Consequently, varying blood circulation is critical for overall heat management in the body.