Well, we speak such a sentence to show the hype of how cold can it be in the winter season, even though it makes no sense. It would have been best not to analyze it scientifically, but still lets do it. 0 degrees celcuis = 273.15 Fahrenheit. Twice as cold would mean half as hot = 273.15 / 2 = 136.57 Fahrenhiet ( Accurate to 2 places of decimal). So the temperature would have been 136.57 - 273.15 = -136.58 degrees celcius.
Have you seen Terminator part 2. I might have seen it a hundred times (again in an unscientific way :)). In the climax scene at the end, when the villan (T-1000) gets covered over with liquid nitrogen, did you see his 'Halat'. The same would happen to us.
I am positing some links to previous asked questions in a similar theme :
http://answers.yahoo.com/question/;_ylt=AsHecfkTCHi3JI9AV_8kj6ojzKIX?qid=1005121700355
http://answers.yahoo.com/question/;_ylt=AmzdEtW3C_32v_oovJVOrE4jzKIX?qid=1005120803510
http://answers.yahoo.com/question/;_ylt=AmiRw_m8b1zWL2AzTdYj.WMjzKIX?qid=1005121402342
http://answers.yahoo.com/question/;_ylt=AuZqvqy.8v_NEotnsKK4a0gjzKIX?qid=1005121201886
http://answers.yahoo.com/question/;_ylt=AgTioUQIMmt3KWeM0E0FdBYjzKIX?qid=1005122001628
http://answers.yahoo.com/question/;_ylt=AsqFJuGKYo2eGWpBlbK0n1ojzKIX?qid=1005122100484