Neutral about it. A burn is a burn, not much to do about it. As Reality said, not attractive, but not really gross either. I am more likely to see it and wince. I got plenty of experience with burns. Pity towards those with them.
Just recently I was chatting with one of my neighbors and she had a bad peeling sunburn on her shoulder. It looked kind of gross but not to the point where I was actually grossed out or she looked nasty.