> Breathing through your nose in the cold while walking to class was one of them. After extensive nasal surgery in 2009 this became an option for me again, aft

> Breathing through your nose in the cold while walking to class was one of them. After extensive nasal surgery in 2009 this became an option for me again, after over 20 years when it wasn't. I discovered a less-discussed rider: yes, it seems gentler on the lungs to breathe in through your nose in sub-zero weather, but there is a condition: you should breathe out through your nose as well. Exhaling warms the structures in the nose so it can warm the next inhalation. But, for me, that same sub-zero weather often causes my nose to make more mucus -- so breathing both in and out means a lot more use of a handkerchief, or a nasty snotty moustache. It's sometimes simply not worth it. :-/