Im an EMT and I vape in the ER all the time, especially when I got to deal with some ronchy nurse who has a stick in her ..., Ive seen people vaping in the waiting room alot too. I usually try to be away from other ppl when I vape though, but if no one is around, I say vape away.
I dont vape when I have a pt in the back, simply because they cant see from the back that its not a real cig. and it distracts me from driving, I do vape in the ambulance when we dont have a pt. during down time, and sometimes on the way to a call, not priority calls though (lights and sirens) just because I need to be hands free, and focused
One way ive found helped me with co-workers, and other people is I tell them about it before they actually see me do it. No one has had a problem with it.