When it gets down to 10 F and below, the condensation from breathing makes the hairs in my nose freeze when I inhale. Long ago, when I was in high school and had to wait for the bus, I told a little girl that "I could smell how cold it was." I took a deep sniff, and said, "It's about 10 degrees out."
She was very impressed. She pointed me out to her seat mate and said, "See her? She can smell how cold it is!"