iPhone 4 GSM - Super hot at Top Right!

Hi guys, I've got a 32GB Black GSM iPhone 4 running 6.1.3 with the latest carrier settings.

My iPhone started to get really hot at the top right, where the camera sits, after it keeps on going, the heat spreads all over. - This is not some heat caused by apps, this is a super hot untouchable device.

When I turn off my device it cools down, approx 2 minutes after boot up it gets hot again.

I have tried: Factory Reset, Running without sim, Airplane mode, Draining battery then charging full.


Any Help / Suggestions are appreciated!

Thanks,
PD.