Instead of sweating, dogs eliminate heat by panting. They do have some sweat glands in the footpads, which help with heat dissipation, but only minimally. When panting isn’t enough, a dog’s body temperature rises. This can be fatal if not corrected quickly.
Heatstroke in dogs can be prevented by taking caution not to expose a dog to hot and humid conditions. While traveling in cars, make sure that dogs are kept in dog crates that offer good ventilation, or use a dog seat belt, and NEVER leave your dog in a car with the windows closed, even if the car is parked in the shade. When outdoors, always make sure your dog is in a well-ventilated area with access to plenty of water and shady spots.