The Celsius system is like the metric system very simple to understand. Water freece at 0c and boils at 100c. What fuzzy logic that is behind the Fahrenheit system is beyond me..
We learnd in school that Fahrenheit set the 0F pont at the equivalent of -17c because he didn't think it coult be any coulder than that.
Well, from my own experiance in the norwegian army some 20 years ago, it CAN... I have been out on what we call "military camping" in -45C (thats about -48F.. remember my remark about logic??).
You pee walking sticks in those temperatures..
I was in a vehicle maintainance crew, and one time during the "spring" there came in to our camp a truckload of US Marines(some NATO gathering). The temperatur was around -20c and they had been on the back of the truck traveling for about an hour from the airport. They where dressed up in there complite warderobe, and freecing like hell. A couple of us thought we would have some fun with them, so we parked another truck behind them. We had taken of our jackets, and with only trousers and a thin shirt we climbed out of the truck, laid down in the snow, grabbed the front bumper and draged ourself under the engine and discussed some parts we had to order and really took the time to do it right. After a couple of minutes we where nearly freecing to death, but the coments coming from the marines where hillarius. I think we manifested some myths about vikings and norwegian soldiers capability in winter conditions that day...

Learned some new american words too...