My child and I both have asthma and a red blood cell disorder.  When the mask minder at the door at Walmart says "Put your mask on, please". We say "Asthma" and are told "Ok, have a good day!"  Now, the Karens inside the store are a different matter!  BTW when Walmart started with the mask minder at the door (my child calls him the bar bouncer b/c they hired a big dude to stand at the door) they closed all entrances but one.  So now everyone is herded in and out through the same choke point.