Q: Iphone 5 gets heated up

Hello NOV NMP,

Thank you for the details of the issue you are experiencing with your iPhone.  Depending on the warmth of the iPhone, this can be normal behavior. The following article explains warmth while charging and using other functions more in-depth:

iPhone, iPad, and iPod touch (4th generation): Keeping device within acceptable operating temperatures

http://support.apple.com/kb/HT2101

For the situation you described, I recommend restoring your iPhone as new.  This will help you identify whether it is a hardware or software issue:

iTunes: Restoring iOS software

http://support.apple.com/kb/HT1414

Additionally, I recommend backing up any important information from your iPhone before restoring:

iOS: Back up and restore your iOS device with iCloud or iTunes

http://support.apple.com/kb/ht1766

Thank you for posting in the Apple Support Communities.

Best,

Sheila M.