Also....for those of you who have issues breathing the cold air comfortably, you may be able to overcome this.
I used to have the same issue, where i would try to keep my mouth covered while riding in colder temps, because if i didnt, i would be coughing and hacking for the rest of the day post-ride. This made riding more difficult (to get proper air/oxygen while covered) and less enjoyable.
After a few seasons of struggling with this, i decided to hold off on the face coverings as the temps started to dip below freezing. I had a day or two of coughing/hacking that were not too severe, as the temps were not that cold yet. To my surprise, however, after those first couple of chilly ride, i was able to continue riding comfortably in the cold temps without a covering. No post-ride coughing or lung issues. It was as though my body simply hardened up and acclimated to the conditions - easing into winter, if you will.
Now i can hold off on covering my face until it is really cold, making riding much easier without overheating or starving for good airflow.
I know this sounds a bit too good to be true, but might be worth a try for those struggling with this who don't also suffer from a chronic asthmatic issue.