Ah, I am sorry for that. But raised scales are often a sign of serious internal problems., It often means the fish is unable to regulate his own water content, osmoregulation, and there is very rarely anything you can do about it.
I agree, seeing it on the head first is a bit odd, but if a fish has dropsy, all the scales on the body will rise, and the eyes will pop as well. First time I ever saw a case, I had no idea what was happening, so the poor danio was pretty much a pinecone by the time I learned what was wrong.
At least I was able to euthanize the fish before it suffered any more.
Bettas do like salt in their water and it is a good general tonic and treatment for many things, but the heater was not needed. They don't need truly tropical temperatures, unless you are treating for ich or something like that.
I think this poor fish likely had an infection internally and there was nothing you really could have done.
