What would you do if this were your (just!) adult kid? We would take shifts being with him with the keys at the front door at a moments notice. Because he's establish he would probably go to an walk in appointment. (all clinics I've gone to had one.) if really bad. If he wasn't established may even call the urgent cares in the area and see what they say to do. I would keep him home unless he was a threat to us/himself.