Here in South Texas, whenever the temperature drops below 60 Fahrenheit, most people are digging out jackets and sweaters. So to us, extreme cold would be the temp dropping below freezing longer than a few hours.

However, I do remember reading an article in National Geographic long ago about a man who was traveling solo across the Arctic by dogsled. He mentions carrying a rifle in case of Polar Bears (in fact he had to kill one that got way too nosy!). He mentions soaking the action in Kerosene to lubricate and keep it from freezing up. As I said, I have zero experience when it comes to that kind of cold, but that's what he said.

Being more of a "Tropical Bird" myself (I prefer to hunt and fish wearing shorts), if I ever were to experience cold like that, my balls would crawl so far up inside me, it would be August before they dropped again!!!