I have been having the same issue with my Samsung Galaxy Watch. It is a new watch and suddenly started getting heat, which I can't fix. Worse than that, I,m from Brazil and bought this equipament in the USA, that shouldn't be a problem, but apparently they can help me here in my country.
CAN SOMEONE PLEASE HELP ME WITH THAT? I REALLY DON'T WANT LOSE THE MONEY I SPENT ON IT.
Looking at the picture, I would think that you would feel it happening if it is a burn of that intensity.
I would expect that you find out it is an allergic reaction instead.