I went shopping today as well, and knew something was different when I saw hand sanitizer back in stock after being out for months!
I wonder if you have to have an actual professional mask or if you can improvise?
Some people here are going so far as to wrap old shirts around their heads in a pinch. :)
For this one location it must be somewhat legit looking not just scraps of cloth ... homemade are acceptable but must be secure without any vents