Simply Science 7
Dogs do sweat, but they don't sweat in the same way we do. Dogs regulate their body temperature mainly by panting rather than sweating as humans do.
When a dog pants, it rapidly breathes in air, which helps evaporate moisture from the mucous membranes of the mouth and tongue. This evaporation takes away heat energy and cools down the dog's body.
They do have sweat glands, but they are not as numerous or as effective as those in humans. Dogs have sweat glands in their paw pads. These sweat glands play a very minor role in reducing body heat and are not the dog's main mechanism for cooling off. They can cool themselves by seeking shade, lying on cool surfaces, and avoiding strenuous activity during hot weather.
Since ‘man’s best friend’ is less efficient at cooling off than we are, it's important that we provide access to shade and water – especially during these hot weather spells.