Leopard gecko died - help!?

our heating lamp broke a few weeks ago and our gecko was acting fine with just the heat from a regular lamp near his cage. eating normal etc. today because it was warm out i figured he could use a bit more heat... maybe i was wrong- because i think he is dead! at 2pm i brought out his cage and place it in the sun, with a shady area and fresh cool water. at 3 he was laying in his water dish and seemed content but when i checked on him at 4 he still hadn't moved and so i went to get him out and he is not moving or blinking. he is still the right color, i immediately brought him back in to the house and am hoping he is playing dead or something. could i have overheated him?? i feel terrible!! it was about 85 out today where we live mostly sunny. omg please tell me i didn't kill him. it was only 2 hours!! his lamp used to be on for 8 hrs!! anything you can tell me is appreciated!