What is the coldest temp you ever experienced?

I don't remember what the temperature was —somewhere well below zero F. A friend ran out of gas on the way home. I went out to help. While we were dealing with the situation out in the cold, I felt the back side of my right ear explode. It swelled up, and over the next few weeks, it seeped and crusted and hurt like hell. Eventually, the dead skin sloughed off. Oddly, it didn't seem to leave a scar.