I was also thinking it looks old for a burn. My friend who is keeping him moved to a new apartment a few weeks ago and i had not gotten a chance to go buy there since they moved the tank (until last night). I realized today that when they moved the tank they put the heating pad up against the bottom of glass so the pad had direct contact with the tank glass. also, she had not handled him in over a week because he was shedding and was acting tempermental. I am sure this was why. It doesn't look infected (to me at least) and there is no sign of any puss or raw/irritated tissue...just the scab-like scales. And like i said, he does not act sensitive in that area and all other behaviorhas returned to normal. The pad has been removed from the glass this afternoon and once again has 1.5 inches space from the tank.