Couldn't turn it off, the screen locked up.

 

I thought the fridge was a good idea, it cooled it down some, it was still really warm, but it held the phone in check until the battery died.

 

I'd take it to apple at first chance you can still. Power button, and home button. Should reset at all costs if regular power cycle doesn't work.

Gives new meaning to "my phone is blowing up."

 

I had this problem with an Android a few years ago. My mother-in-law had the same phone and same problem. Her's was worse and she replaced it. I stuck with mine but went with an iPhone when it was time to replace. I've never had a problem with either iPhone that I've had.