in the OR or while giving anesthesia they must wear scrubs but in their clinics and outside of OR they wear lab coats with formal business attire underneath.
you would usually wear dress pants and a blouse, top of some sort, maybe a suit and put your lab coat over it... but if your in the surgery room you would where a scrub and crucs or sneakers and a...
So they can protect themselves from the fire. It could be a mild fire or a life-threatening fire and they need to get in to the the building or wherever the fire is fast without getting injured.