iPhone 4S latest software keeps turning off

My iPhone 4S was overheating a week or so ago, I was holding it and it got awfully hot so I put it down and left it for a few hours.

A day ago, it turned itself off out of nowhere, I turned it back on and when I went to use it, it would keep turning off and on and freezing,

Finally today it wont turn on, it gets to the start up part (black with white apple logo) and freezes and wont get any further.

Help?