@j_t_2390@LozzaFox Surgeons wear mask during procedures to reduce the spread of pathogens. It doesn't stop all fluids from passing through, but it does reduce it and reduces the distance particulates will travel. N95 mask are the only mask that stops all particulates.
@j_t_2390@LozzaFox Don't you realize that you release heat when you exhale which causes condensation of water in the air during reezing weather. The 'fog' you see is from the air around you, not from you.