My dogs have been staying inside during the hot days, too. Chipper especially likes to sit in front of the fan and feel it blowing through his hair. When it got really hot, i trimmed his hair short, too, even thought he is usually in the house.
We seem to have had fleas out in the yard this summer, so the dogs have had to have flea baths fairly often. I don't like spraying them with flea spray all the time, but when they go outside, they come back in and scratch.
I have been putting the diatomaceous earth in their dog beds, and that does a good job of killing the fleas, and it is not harmful to the dogs, since it kills fleas with a natural method, and not with chemicals.
I read that sassafras leaves would repel fleas and mosquitoes, so I made a tincture of that in isopropyl alcohol, and have been spraying that on my legs when I go outside where the mosquitoes are bad. I tried it on the dogs, too. I think it helps, but it is not as effective as just giving them a bath. The alcohol does seem to kill fleas on contact, but you can't get all of them, because they hide, so the bath works better.