Another natural shelter often cited for use in an emergency is that of the snow hole. Having built a snow hole in cold but good conditions I would not want to have to make one in an emergency. It takes a lot of time and energy to dig a shelter using an ice axe alone.
High winds and blizzards can make using a tent in deep snow difficult. It is important to know how to make a shelter in the snow. Snow is an excellent insulator and makes a great home. I spent a week using a shelter as a base for winter climbing. It was great to come back to and very cosy. Cold weather shelters can range from simple trenches covered with a few pine boughs to the famous igloo. A simple windbreak can be built to shelter behind during a lunch break.
The snow cave. A trench should be dug into a snow bank. As deep as possible but at least 2m. Snow banks are often found on the lee side of bowls and beside riverbanks. Before starting to dig a shelter assess the site for any object dangers like avalanche or Serac collapse. A few hundred tons of snow and ice falling on your shelter will spoil your day. When digging your shelter it is advisable to remove your mid layer and just wear your waterproof outer layer, digging it very hot work and a wet mid layer will be difficult to dry. Ensure a pole or axe shaft is driven up through the roof to keep proper ventilation. Keep the roof a smooth as possible to prevent drips.
Pictures taken from my Alpine Preparation Course. ©W Jones