If you want to be off duty, be OFF DUTY. if you are ID'd as an EMT or above in OH you are expected to act. Dont be afraid to ask questions or admit you don't know. The squad (what most depts call the ambulance around here) has communications equipment for a reason. If you must, carry a scanner instead of a radio. You dont want to be that guy that hops on the two way every time he sees a fender bender...