Understand -- I'm not a camera repairman. But heat can only be produced by something in the electrical circuitry, and my first stop would be changing the battery. There have been some batteries that have overheated. There are also (a) off-brand batteries and (b) counterfiet "Nikon" batteries in the market. I'd make sure the battery being used is an authentic Nikon-brand battery from an authorized seller. Charlene might also check the conditin of the battery as indicated by her camera menu. I can't imagine outside weather related heat being the issue, as I used Nikon DSLRs in Baghdad in the summer of 2003 and it doesn't get much hotter than that place.