Best not to think about the windchill, estimated to be around -35.
Stay indoors, and if you're out-of-doors, avoid exposing much skin -- full-coverage balaclavas are useful, esp if you want to cultivate a badass look.
Interesting fact: When the temp drops to about -25, it's very hard to skate. This is 'cos a skate blade glides on a thin film of water generated by the heat from the pressure of the narrow blade on the ice. Mind you, when it's -25, it's hard to tie your skate laces, because fingers don't work very well then either. Nor is it much fun skating into a headwind at anything below -15... (-15 with a wind is usually my cutoff point for X-country skiing as well.)
As above, brew some hot chocolate & stay indoors, maybe adding a dollop of sherry or brandy to the hot chocolate.
As a PS, Anto: The good thing is that the days are usually sunny when it's as cold as this. Today, we have a blanket of snow, a bright blue sky, and bright sunshine. I'll go for a walk this afternoon, scarf across face, wearing my -35 boots and mittens (these items come with an estimated temp rating, useful when you buy them.)