A mask is never just a mask

News Snapshot:

Open this photo in gallery: People wear face masks as they walk through a subway station in Montreal, on July 17, 2022. During the pandemic, many believed masks might become the new normal.Graham Hughes/The Canadian Press Thomas Schlich is the James McGill Professor in the History of Medicine at McGill University, and a former practising physician. Bruno J. Strasser is a historian, a professor at the University of Geneva, and an adjunct professor of the History of Medicine at Yale University. They are the authors of The Mask: A History of Breathing Bad Air. On a full bus in any...