Please access this video at https://youtu.be/mHF1FE4sCDs if it is still available. It is posted here in case it is censored at its original location. This is a real education on the proper use of masks and the real dangers of misguided use. These ladies have almost four decades of combined experience in training, testing, and educating over 10,000 clients in masks and other PPE (Personal Protective Equipment). See their other video posted here for an even more in-depth interview which includes the question of legal liability when masks are required without proper medical evaluation.