Put it this way. Some of the armed forces that encounter these fire threats on a daily basis in war zones banned their use by personnel.
They even went as far as developing specific flame retardant suits for vehicle crews and anyone travelling in them for extended periods of time.
I wont wear anything other than cotton when working around flames and inflammable materials (oxy acethlene, welding, fuel transfers, composite layups).
Great for running around and training, or when I'm doing sports, but on the job, a big no no.