Missing scales?

[Bogertophis]

When you say heal, do you mean the scales coming back or..? I've never experienced this so I'm not sure what it should look like once healed

When snakes heal, they do so by repeated sheds, but scales don't usually grow back- you'll usually see a scar (of smooth skin) where the wound was.

If this was a blister, that's something that burns may cause too, so double-check your temps. for safety, but burns are usually on the belly of a snake, unless there's overhead heat of some kind???