My guinea pig got left outside in 91 degree heat for about 10 hours on accident is he going to die?

I told my bf that he cage needed changed and he took the cage outside to clean it then fell asleep. We got the guinea pig and gave it a bath and it's standing around in it's cage. But it used to be really mean and run around really fast if you tried to touch it, and it would bite the hell out of me. But now it just stands there and let's you pet it, it doest move or anything. I can tell it's still alive cause when you poke it in the eyes it blinks.