Do you have a basement? Basements are cooler than the upstairs of homes.
Make a homemade a/c. They look goofy but everybody says they work.
http://www.youtube.com/watch?v=zR9CA8lJGvs
There are a bunch of links like that on youtube. It's not super expensive, will probably cost you $30 or $40.00. Well worth it to keep your chin safe and cool. Probably will feel pretty good to you too if it's going to be that hot. One of those is supossed to easily keep a small room cool, like a bedroom. Just stock up on ice.