That means that this supervisor is an immature, uneducated ***** to put it in the nicest form. Go back to school is what they have to do and learn some manners. People do get sick from time to time. Maybe she has had it and just took it out on you. Either way is uncalled for that kind of attitude. I tell you, no class. If I were you, I will call her out on it and ask " What exactly you meant by that", even though you might have an idea and see how she answers you. Provide documentation if you went to a doctor and if not take it as a sick or unpaid day. No need to lose a job over that. Been there with bosses that talk to me like I am their child. Angry fire lol. Take is easy and in stride.