I don't know what the temp was but spit cracked before it hit the snow, pee froze in little icicles that fell over and made tinkling sounds (origin of tinkling?), and I took a pot of boiling water off the fire, poured two cups into my cup, put the pot back on the fire, and there was a crust of ice on the cup when I picked it up.
Dry Fork Divide, 7000', Bob Marshall/Scapegoat wildreness boundary, Montana, Dec 27, 1976.