PROTIP: in extremely cold weather when the air is so dry it'll give you a nosebleed if you don't have a humidifier in your home, N95s, KN95s, or elastomeric respirators can be a real lifesaver (metaphorically, unless you have a severe clotting disorder in which case it might be literally?).

It's almost like having a pretty decent humidifier strapped to your face. So much better than getting a painful nosebleed from cracked, dried out mucus membranes.