A participant has her oxygen saturation measured, during an event organized by the local medical association, in order to support the use of protective masks, in the northern city of Thessaloniki, Greece, Saturday, Oct. 3, 2020. Lung doctors staged a public demonstration of the benefits of face masks by fast-walking a distance of 2 kilometers (1.25 miles) through the city center aiming to debunk a widely-circulated rumor by anti-mask conspiracy theorists that wearing one left people short of breath. (AP Photo/Giannis Papanikos)
Featured Photo Galleries
