I recently posted about battery draining in a few hours after installing CM11. I was wrong. The shutdown was caused by overheating and not by a flat battery. I have now tried both the original samsung battery and a hi-power battery and swapped between the two.
Over the first few days of owning my g3 I had no problems up until recently. Every time I play an app or video now, the top half of my screen and top half of the back side of the phone get extremely hot. Also the power button since it's metal/plastic is the hottest point. Any tips on how to fix overheating? Or even just reduce it slightly.