When the summer is sizzling hot, dogs are greatly affected and we should be aware of that. Particularly in the late morning until early afternoon, we provide our dogs with an electric fan of their own. And the water for drinking is cold water, sometimes we even put ice. For big dogs, a cold sponge bath will greatly relieve the heat inside their body especially if you are outdoors like is you are strolling in the park.
Be conscious of the summer heat. It can kill your dog and it's just negligence on our part if that happens.
So you'd just give your dog a wet sponge or wet towel rubbing? I don't think that would be enough. A dog needs a full bath especially if the fur is long. Our vet advised that since it's the summer in our country, it's okay to give my dog a bath every three to four days. We also provide cold water with ice because the dogs here at home likes to play with the ice cubes. They're indoor pets so leaving them outside is a definitely 'no'.
Keeping pets cool in extreme heat is always going to be difficult, but I think with a bit of common sense it's achievable.
The main thing is making sure that they have plenty of fresh, clean water to drink and they have a lot of shade to lie in. I've even gone so far as to leave the curtains shut and left the windows open when I've gone out in order to make sure the pets are as cool as possible.
Agreeing with everyone above, I have read and heard many different people that if you do plan on taking your dog out on a hot day, check the temperature of the ground. If you can't hold the back of your hand on the ground longer than five seconds, it is too hot for the dog to walk on. Just a helpful suggestion.