RE: Idea's on keeping your dog cool during the summer
My Son in Law bought a children's sand box at a garage sale, it has a lid to cover it so the cats stay out of the sand when it is not being used.
He bought this to make a swimming pool, cool off tank for their little dogs. It works great, and when they aren't around to keep a check on them, they put the lid on.
I was reading an article about dogs getting over heated fast if left in a car even with the windows cracked. If it is hot out, do yourself and your pet a favor and leave them home. The article also gave some tips on how to help your dog cool down if this happened. One was take a cool wet rag, and rub it on the inside of the dogs legs, and on his tummy.