[SkyDancer]

Normal O2 levels are between 95-99%; so wearing a mask lowers it 6%; two masks 12%. You’re in COPD area with two masks.

[PIF]

Now do the wear the same number of masks while sweating and breathing hard. Fun, right? See how much bacteria you can inhale in an hour of intense exercise, winner gets a prize from a surprisingly skinny figure dressed in black ...

[Graybeard58]

Normal O2 levels are between 95-99%; so wearing a mask lowers it 6%; two masks 12%. You’re in COPD area with two masks.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

And if you already have COPD, one mask is unbearable.