iPhone turns off won't turn back on
My iPhone 4s has repediately turned off and will not turn back on. I've had to cold start it after many failed attempts (holding keys down until apple logo comes up). I know this is not right. I have plenty of apple products that I do not have this problem with. It has done this on a low battery as well as a charged one. Even holding the keys doesn't mean it will come on for me. It really is a problem. Anyone experienced what I'm going through?
iPhone 4, iOS 5, This is an iPhone 4s