Yes, humans and dogs have a few things in common.  We both have hair.  We both have skin.  We both sweat (sort of).  But there are four distinct differences between humans and dogs when it comes to temperature moderation.  So put the clippers away, your dog could be one Mohawk away from heating up like a solar panel.

1.  Sweat Glands

Humans: Humans have sweat glands on their skin, so they are able to cool down all over their body.

Dogs: Dogs only have sweat glands on the pads of the feet.

2.  Evaporative Cooling

Humans: Humans will sweat when their body needs to be cooled.  The sweat then evaporates, displacing heat as it vaporizes.

Dogs: Dogs only sweat through their paws.  Their main mechanism for cooling down is the evaporation that occurs by panting.  As a dog pants, the moisture in their mouth evaporates, cooling them down.

When a dog pants, evaporation causes the heat to dissipate at the mouth, cooling down the dog

Because a human is covered with sweat glands, heat dissipates over the entire body

3.  Average Temperature

Humans: Humans maintain an average body temperature around 98.7°F

Dogs: A dog’s average temperature is 100 – 102°F:

4.  Hair

Humans: Though humans have hair follicles on almost the entire body, evolution has caused us to lose most of our “fur” for the purposes of keeping warm.  The hair on our heads still functions according to its original purposes, however, which is to insulate in the cold and protect from the sunburn in the sun.

Dogs: Being covered in hair actually acts as insulation from the heat (note: fur also protects against biting insects and sunburn, so shaving your dog is generally not a good idea). In fact, the topcoat of hair is often referred to as the “reflective layer.”  When it’s cold out, a dog’s hair will stand up, trapping heat and creating an insulating blanket around the dog.  In the heat, the reverse happens and hair lies flat.  A double-coated dog will shed the undercoat in hot months to assist with cooling.