Smoking in an ambulance is plain stupid.
Oxygen tends to saturate every thing in the patient compartment.
One spark from a match or cigarette could very easily start a fire that would burn with great intensity. I don't think it's worth the possible loss of life, equipment and the liability it creates. I'm sure you will find some rules against it. Looking for any Federal restrictions against smoking on ambulances by crew or patient. Smoking in an ambulance is plain stupid.