Ok, point taken as far as HEMS goes.
But the initial question was if a patient has to be transported from an oil rig and he/she has been diagnosed. The carriage in a controlled environment like that is pretty straight forward I think.
I wasn't judging the usefulness of the mask you where referring too, I was more arguing in the lines of: nice to have, but the patient doesn't have to wait/suffer because my new face mask has a 3-day delivery...
All I'm saying is, that the majority of the cases probably can be dealt with safely, with the normal protective gear that ground units use.