3. Introduction Ducks, geese and other waterfowl swim or stand in water that is cooler than air
on hot days. As blood circulates through their feet, it cools them down. A similar
thing happens to mammals with big ears like deer and cottontail rabbits. Air
blowing across their ears cools the blood before it re-enters the body.
4. EXAMPLES
Dogs don’t use their skin to perspire, like humans, because of their insulating coat.
Their coat keeps them both cool in hot weather and warm in cool weather. Dogs
do have sweat glands, located in the pads of their feet and in their ear canals,
but sweating plays a minor role in regulating body temperature.
When the temperature is very hot and especially when it is humid, everything heats
up…including a dog’s body. His body responds by trying to cool off and it
basically attempts to use conduction, convection, radiation, and evaporation. He
will seek a cool place in the shade to lie down to absorb the coolness
(conduction). His blood vessels will dilate in his skin and tongue bringing hot
blood close to the surface radiating his internal heat. He will seek out fans or
breezes to blow air to transfer the heat from body to air (convection). He will
pant to bring air into his upper respiratory system to evaporate water from his
mucous membranes. He will drink a lot of water to compensate for the
evaporation.
