>>From previous offline discussions, the non-medical hypothesis is that wearing a mask has the effect of being in thinner air, effectively working at a higher altitude, known for inducing fatigue.<<
My insight is personal, as that’s exactly what happened to me. I’m near 80, cannot breathe in the things, and nearly passed out in a store. Fatigue from it also genuine, lasted all day. Will not try again. My freedom to breathe trumps their freedom to be scared.
I feel “smothered” & a bit claustrophobic in a mask - I haven’t been wearing one. Also, based on a lot of sources I’ve seen, a cloth mask is like putting up a chain link fence to keep out mosquitoes.
That being said, with Gov Blackface imposing masks & I do need to go to the store on occasion, I will be making one out of “flour sack”. It’s a level above cheese cloth - I use it for straining. It will be one ply & I’ve already checked it out - does not impede breathing at all. :-)