Perhaps consider this:
I used to run a motorcycle clothing and accessory store in the West End of London. Respro masks were all the rage with cycle and motorcycle couriers (the original masks were not cut away like the versions available now).
Our store also equipped Paramedics and Police (with specific gear) several of whom spoke about cyclists and motorcyclists involved in road traffic accidents, that would die, despite the fact that their injuries were not life threatening!
They died because they choked on their own vomit, as a result of injuries sustained during their accident, yet were unconscious and could not remove their masks, scarfs or balaclava's (ski masks) which covered their mouth and nose!
The emergency workers really hated these masks, having to deal with the unintended consequences of their use.
I wear a balaclava, Buff or scarf when walking or paddling in cold weather, but I never, ever have my mouth or nose covered when motorcycling or cycling.
Sorry if this sounds morbid, but I believe that the issue has relevance.