What kind of mask was he wearing? Probably an N-95 and for an extended period of time. Wearing a cloth or paper mask for a 30 minute grocery run is nothing compared to the many medical professionals who wear their masks for 8 hours straight.
I’ve carried heavy groceries up 2 flights of stairs while wearing a mask. Seems to me if hypoxia was a serious concern I shouldn’t be capable of doing that.
Studies say ...
N95-masked health-care workers (HCW) were significantly more likely to experience headaches.
See post #79.
Cloth masks don’t seal. Period. You know that when you see poor Jon Karl at the WH press briefings with his fogged up glasses. His glasses fog up because the mask leaks. About as effective as wearing a mask with an exhale valve, which is not effective for protecting others.
I’ve worn masks as PPE, if you can’t pass the fit test you can’t wear the mask! That includes particulate filter masks.
Besides that corona virus is much smaller than most masks will filter out.