...it's because I'll be frozen in a block of ice someplace. I have a bunch of outdoor work to do over the next few days, and temperatures here in Saskatoon will not be pleasant. Today's predicted high is -19.
Of course the truth is that I've been out in weather like this for extended periods before. I'll have access to a car for shelter. And I've got enough brains in my head to get out of the cold for a while if I think things are going bad.