The best way to survive being in a very cold environment is to be fully prepared before you find yourself in such a situation. To prepare fully for very cold temperatures you have to consider low temperatures, wind and the amount of moisture in the air. All three of these contribute to survivability when the temperature drops.
In general, to survive very cold temperatures means protecting your body from loss of heat; thus, people need to wear the proper clothes. For the most part, this means wearing sufficient clothes to ward off not just cold, but windy conditions as well. To survive people need to protect their bodies literally from head to toe. Hats that hold in heat should be worn, as should something to protect the face if there is wind. Also, scarves serve to keep the neck warm. Below that, undershirts, shirts, over-shirts and jackets are needed to keep heat from escaping the trunk. Next, long-johns are good at holding in heat if worn under windproof pants. Pants made for riding on snowmobiles are good for this. Because feet are so susceptible to cold, proper socks that hold in heat, but don’t cause perspiration work best, covered with waterproof, well-insulated boots. For hand protection, it’s best to wear insulated mittens rather than individualized gloves because they hold the heat in better.
Once you have your body protected, you need to consider what sort of shelter you will use for the time you will be in the cold. Tents that hold off the wind, but can hold in the heat from a small heater are ideal, unless you plan to be out a long time. In that instance, you’ll need something a bit more permanent and durable.
To survive very long in your shelter, you’ll also need a heat source of some kind. Portable heaters are available at camping stores, as are burners; even large lanterns can help. Burning wood also produces heat, but the smoke will likely kill you, so it’s best to stick with heaters.
To survive in the cold you’ll also need food that is high in calories and has a lot of protein. This is because the human body burns a lot of calories in trying to stay warm, and if there isn’t a lot of calorie burning going on, the body starts to get cold. Consider the difference in eating a large spaghetti meal versus a salad. The spaghetti dish will keep you warm for hours, (the noodles will heat you up in the short term, the meat will heat you up for the long term) while the salad won’t keep you warm for even a few minutes. Also, for a quick infusion of calories that will heat the body right away, keep a lot of chocolate candy bars handy. They turn on the bodies burners almost right away.
Finally, never drink anything cold when out in the cold because doing so lowers your body temperature immediately. Always drink something at least as warm as your body, if not hotter. Doing so will maintain or increase body temperature.