An evaporative mechanism involves animals losing water from their skin, mouth, and nose by evaporation into the air. Evaporation removes heat and can act as a cooling mechanism. For instance, many mammals can activate mechanisms like sweating and panting to increase evaporative cooling in response to high body temperature.
- In sweating, glands in the skin release water containing various ions—the “electrolytes” we replenish with sports drinks. Only mammals sweat.
- In panting, an animal breathes rapidly and shallowly with its mouth open to increase evaporation from the surfaces of the mouth. Both mammals and birds pant, or at least use similar breathing strategies to cool down.
In some species, such as dogs, evaporative cooling from panting combined with a countercurrent heat exchanger helps keep the brain from overheating.