In -75° F weather, we made camp with care and made sure to have a good supply of firewood on hand. Finding a standing dead tree became an important priority toward nightfall. But we let the fire go out in the tent at night, and we slept fully dressed, still wearing our sheepskins, dozing fitfully and waiting for morning to come.
It is astonishing how many people die in the mountains or in the north surrounded by one of the best insulators snow. Find a slope or a hillside where exposure to the wind has packed the snow well and dig out a burrow. Just as in an igloo, the temperature inside can quickly rise to around 32° F, even in -50° F weather, particularly if you have a candle. With a bit more time and some wood you can make yourself quite a good shelter. It takes only a few branches, although a tarp helps. Site the shelter at the foot of a rise and dig down to the ground. That way, a current of warm air will carry the smoke up along the slope and reflect the heat better into the hole.
Dead trees that are dry and still standing make the warmest fire.
Although the extremities feel the cold first, it does no good after a point to add more layers of gloves when your hands are cold. It’s the rest of the hodv that needs to be kept warfn.
A Siberian trapper taught us how to make these boots, the warmest we ever found. They are sewn together from squares of half-inch-thick felt and work beautifully even in the bitterest weather.