How hot can kittens handle?

its starting to get really hot in my house and it could get to 90 degrees or even hotter but its cold in the morning. i have a kitten hes about 2 or 3 months old and he doesn't drink a lot of water so im worried he might die because its too hot. so i want to know how hot a kitten handle and how to help keep him cool. i try to wet him a little with water and he doesn't like it.