Have you looked into a "swamp cooler"? That is what I use in the summer to keep ferm temps down. It's basically a large tub filled with water. You place bottles of ice in there and rotate them out once melted. It's a good way to keep the temp in check. How warm are we talking? I usually never let any of my ales get over 70 but I have gone as high as 68. I like to keep them at the low end of the ranhe usually, like 62-64.
Edit: There are a few styles where ferm temps can be higher and that is ok. Saisons are supposed to be in the 80's and Belgians can ferment well in the 70's.