Call it the naked rule: If you have to put clothes on, you should put on a mask. That’s the shortcut we learned from talking to experts about when, exactly, masks are needed. After all, the general guidance — wear a mask in public — can be confusing: What exactly does public mean? What counts as leaving my home? Does it mean going outside? And for people who live in apartments or other multi-home buildings, it means wearing a mask when going to common areas where you might run into others. So even if you don’t leave the building itself, or feel like you’re going anywhere — just downstairs to throw out the trash! — you should put a mask on when leaving your apartment. It’s about your possible exposure to neighbors, and lack of control over that, said Suzanne Willard, associate dean of global health and clinical professor at Rutgers School of Nursing. To read the full article.