My wife is always to hot to sleep, yet Im not.?

Im 6'4" 215 lbs and its 80 - 85 degrees in our bedroom. My wife is 5' 3" 130 lbs and says its way too hot to fall asleep. Why would she be too hot yet Im fine, I admit its warm, but not too hot. We cant turn on the AC because our 1 year old always gets sick when we turn it on, plus we want to conserve energy and money. Is there something about her diet or lack of excersize that she can change to help her sleep?