You take a risk every time you put the mask on and off.
If you have a long time between stops that may be worth it. We try to arrange hubby’s errands to be efficient to avoid that.
YMMV.
OK, Agnes why do you think it is a risk to take the mask off and put it back on? In what way pray tell?
After wearing them in one place, we take the custom fitted masks off before getting in the car and put them in a bag before sanitizing hands. We carry several clean masks and put one before going into the next place.
Some people have been paranoid or even hostile about other people wearing masks and minding their own business, so I’m going to put check valves in them and routinely insert the better filters in the pockets. ;D