Internet sharing Off, Bluetooth Off, Wifi Off, NFC Off, Location Off, Airplane ON. Brightlight Low: Battery Saver ON, Touch Sensitivity: Normal, no any background tasks are running. The phone is still feeling warm or overheating. Something is not stopped, still using CPU power until soft reset.
Nomally, Internet sharing Off, Bluetooth Off, Wifi ON, NFC Off, Location On, Brightlight Auto, Battery Saver Off, Touch Sensitivity: Normal, 4G lte full speed. the surface temperature will over 50 degrees after 5 mins, no game, no video, just using facebook, twitter & some news apps. If you are keeping to use around 15- 30mins, the phone will hang and reboot automatically.
As soon as 3G/4G is in use, the phone starts cooking. Various reports claims that this is a CPU bug, and not the phone itslef, and that GDR2/Blue is set to
fix this issue.
http://forums.windowscentral.com/nokia-lumia-920/203480-2.htm
Hope, that's true.