Today my fish got stuck behind the heater. I couldn't find him, and I was worried he had jumped out, but I then I saw him behind it. At first he struggled a bit to get out but then he figured it out and swam out. He's swimming fine, but he has a HUGE white spot on his head now. I can't tell whether the scales are burned or if they just fell off or what?
Here's a picture (not clear, but you can kind of see it):
But anyways, my question is, what exactly happened? Did the scales just fall off or is he hurt? And is there anything I should do for him?