Minus 87 Fahrenheit during a military exercise called "Brimfrost" 1989. Out in the Tanana flats outside Ft Wainwright, near Fairbanks, Alaska. -87F. And that was *not* "wind-chill" either. That was in dead-still air. It was so cold the wind didn't even blow. It was so quiet, you could hear your own heartbeat. I pulled a machete out of the ahkio sled to cut a couple of saplings (to make a tripod for the gas can for the stove to heat our ten man arctic tent). On the first swing it snapped like a glass rod. I still have the two pieces, mounted on a plaque. The whole exercise came to a stop and became just a matter of survival. And these weren't "cheechakos" either. This was for a unit trained and equiped for arctic warfare operations with guys with many winters in the Yuke. I could only let people out of the tent to use the latrine, and only in pairs. Exposure time for bare skin was in seconds. Out of the entire brigade, there were only two Small Unit Support Vehicles (SUSV) still running. Mine was one of them because I was an absolute demon when it came to preventative maintenance in the arctic. The Yuke is one of those places that will, no-shit, kill you graveyard dead just for standing around looking stupid. The division brought over a factory rep from Haaglund Und Sohns in Sweden, to ask him why the arctic vehicles they sold us didn't seem to work in the arctic, and the guy said, "They were only designed to -25F, maybe -50F for short periods! You people are fucking maniacs!"