Until you have experienced -58°C WITHOUT the windchill, you do not know cold, Boston or no Boston
Though -50 temperatures tend to minimize the windchill as a side effect, not counting polar regions. Usually -25 degrees with strong wind has proved to be much worse than -40 degrees with no wind. Add some humidity by the seashore and it's also pretty cold. There are people who came from the place that usually has this -40 degrees of cold, recent minimum was -52, and they say this is worse since in their place there was no wind and the air was dry.
And speaking of feeling cold, I think even a better version is marching with the full gear in the moderate between rain and snow (I always forget this word in English, sleeze?). Then make sure temperature drops below -25 degrees in a moderate windchill in the evening after having marched the whole day and start putting up the tent. And finding some dry wood by which the heater could be warmed is always a positive thing in wet, cold and dark night...
And when you finally get to the sleeping bag in a warm tent (though windchill tends to blow still to your face - even if you are in sleeping bag), somebody wakes you up and tells its your time to go guarding. And of course the guarding persons cannot stand up, they lie on the ground. That was the night when I learnt what "cold" means. I wonder how I never got any frostbites to skin, though I suppose it came pretty close by times. The skin on the finger tips cracked several times during the service.
Ah, memories.
Though someone could write here the opposite stuff, like hell it was like +50 degrees the whole day and that was really ****! That would be something to read also.
Mika