They jog at minus 5, play football and futbol on frozentundra, dribble basketballs in fingerless gloves and jump in the ocean on New Year's Day and Jan. 2.
If you go higher than that, there are other tipping points, especially the release of carbon in the tundra and the things frozen in the tundra region, and that tipping point means it becomes very nonlinear and all of a sudden--boom!