No, literally a face mask, so that people know that you aren't going to give them the virus. I don't know if it's mandatory to wear a face mask.

But it doesn't seem like it would be too different from what always happens in Chinese New Year in Beijing. All the shopkeepers aren't from Beijing originally, so they close shop for two weeks and go back to their hometown. There's pretty much no restaurants open, except maybe chains. And people are shooting off fireworks all day, so the air is just as polluted as always (generally well above the level of an airport smoking lounge in the winter), so you want to be wearing an N95 mask anyway. (Generally if you can't see the mountains around Beijing, you should consider wearing an N95 mask)