evidence: Face masks provide protection against transmission of respiratory viruses. Additional steps to help the spread of respiratory viruses include hand washing, respiratory etiquette, and avoiding others when you are sick. [...] None of these three types of face coverings works as well as a proper face mask. A good mask has a double layer of washable, breathable fabric that helps keep the wearer from spreading potentially infected droplets into the air. A bandanna tied around the face does not work as well as a mask because it is open at the bottom. A gaiter (a tube of thin, stretchy knit fabric that can be worn around the neck and pulled up to cover the nose and mouth) is usually too thin to provide adequate protection. Likewise, masks with exhalation valves can allow droplets to escape into the air. [...] Although being fully vaccinated and/or boosted reduces your chance of catching or spreading the coronavirus, it does not eliminate it entirely. If you are infected with the coronavirus and do not know it, a mask keeps your respiratory droplets and particles from infecting others. Check the mask recommendations in your area to help decide whether you need to mask.