Always make plenty of cool, fresh water available to your pets. If your dog is outside on a hot day, make sure they have a shady spot to rest in. Doghouses are not good shelter during the summer as they can trap heat. You may want to fill a child's wading pool with fresh water for your dog to cool off in.
You will also want to avoid strenuous exercise on extremely hot days and try to avoid prolonged exposure to hot asphalt or sand, which can burn your dog's paws. The best time to exercise your dogs is in the early mornings or evenings, when the sun's heat is less intense.
Keep in mind that dogs that are brachycephalic (short-faced), such as Bulldogs, Boxers, Japanese Chins, and Pekingese, have an especially hard time in the heat because they do not pant as efficiently as longer-faced dogs. Brachycephalic dogs should be kept inside with air-conditioning.