Losing the hair is pretty traumatizing. However, the child’s attitude towards the whole thing depends alot on the way the adults around him deal with the situation. The main goal is to keep the air “light” and to be open about it and even joking about the situation at times. Another point is to make sure that you keep reiterating to the child how cute they look (which is really true!) even once they’re bald, and explaining that it does not define them for who they are.