On an elk hunt in CO it got down to -45F and on another time during a SD predator hunt it was probably the same temp, but we didn't look to see how cold it was. On the elk hunt, my ammo would not fire. I tried to fire 4 different rounds and all that happened was I dented the primers. After this experience, I kept my ammo inside my parka and loaded it as a single shot when needed. That worked for the second elk. The SD hunt was very memorable. We left the truck and plodded through knee high snow to the base of a haystack. Piled some snow up in front of us to break the probably 40mph winds blowing in our faces. After about 5-10 minutes of the snow blowing in our faces, my cousin and I decided this wasn't fun anymore and decided to leave. We got to our truck just to discover a flat tire. Took the spare tire from under the truck to discover the wheel was full of ice covering the stud holes and too thick to fit on the hub. We tried to hammer the ice out of the center of the spare wheel but the ice was so hard from the cold the hammer just ricocheted off the ice and hardly nicked it. So I finally took my .22 pistol, held it up to each stud hole in the wheel and blew the ice out of each hole. However, there was still ice remaining in the center of the wheel that caused the wheel to wobble while driving. So we drove a few yards, retightened the lugnuts, drove a little further, tightened again, and again, until finally the tire stopped wobbling and we were able to drive into town. We both looked at each other and concluded that was fun. LOL