Nuh-uh, I've seen it happen, about grade 4 or so. Someone dared the kid everyone picked on (a Trek fan, so go figure) to do it on the railing outside the community club. Damn, but he bled a lot.
Y'know, I'm sure in the past it's been this cold, but I honestly don't remember it being -50 C with the windchill ever. Lots of time in the -40s, but never that 5 as the first digit. Hell, the cars are plugged in INSIDE the garage
-50 C: frostbite can occur in less than 2 minutes
Geez, it's even buggering the cable connection