My phone heats up when:
1-Connecting to charger
2-Opening the phone and start browsing for anything(apps, games, internet). games are the most cause of this heat.
3-Sometimes when I sleep I put the phone under the pillow(for alarm), then I sleep with 100% battery level, I woke up and the phone is about to melt, battery indicator says 10% or even less.
All of that heat problems causes unreasonably battery draining as well!
NOTE: When I turn off the phone and connect the charger, it doesn't get any heat or battery draining and the phone charges correctly.
I don't think its hardware or battery problem, cause when I turn off the phone I don't get any problems at all.
Any help would be much appreciated.