In the winter part of my job is monitoring weather conditions, temperature, snow, wind, etc. and the coldest I have ever seen (in the last 12 years) is -26° Celsius (not factoring the wind). This year I had the "joy" of seeing -34° Celsius (again not factoring the wind) and I can tell you that you can have the heat on high but you can still feel the cold coming through the door on the truck!!!!