Well, you make yeast starters with 100 F water, so I'm assuming as long as your fermenter doesn't get above 100 F your yeast will be fine. BUT from what I've gathered, fermenting at temps too far above 70 F will result in a faster finishing fermentation AND off flavors that you don't want. If you have a basement that'd probably be the best place to stick it. My batches have done fine with the 70 - 73 F ambient temps in my basement. Fermentation itself should never produce a noticeable increase in heat. Wild yeasts or bacteria will (ie: compost piles get really hot while beer fermentation should carry out at near ambient temperatures) Get yourself a dual-scale temp strip and stick it on the side of your fermenter. That's a great way to know what temp you are fermenting at.
SimpleCJ - "All ya gotta do..... is just DO IT!!"
Coming soon... - Caribou Slobber, Dunkelweizen, Kolsch
Tertiary - 6gal Perry - 5gal RyePA
Bottled/aging - 3gal Appleberry Wine