"What’s with the surgical masks?", I keep thinking to myself.  I've seen them in Chinatown in NYC.  I know that folks there wear them to prevent others from catching their cold. Oh, there’s an announcement on the subway telling people to wear surgical masks if they have a cold or cough.  "Thankfully everything is repeated in English!", I gratefully reflected.  Wait, there are a lot of people on the subway wearing masks.  Do all of these people have colds?