BBB not starting up anymore


I have a BBB which suddenly wont boot anymore.
It does show some strange behaviour, connecting power supply makes CPU get hot.
The uart log at the same time shows that it hangs at starting kernel.

However the BBB still works perfect when i put it in the freezer for a minute and then boot it.
It then starts up without any problems, not giving a single error.
However after a while when it gets warmer it suddenly stops working and i get the trace below.

I am running latest archlinux.

This is not normal operation. Where is the board placed when this occurs?