Once again, Calvin can say it better than I can:
It really is that cold. This morning, walking to class, I itched what felt like a perpetually runny nose. Through my mammoth catcher's mitt gloves, I flicked the tip of my nose to the side, and felt a small tug from the other side, a cold pull. Tiny, barely perceptible, but it was there, like a swab of glue in my nostrils, cementing them together.
My boogers really had frozen.