An adequate shelter means your pet is kept warm, dry and away from drafts. If your pet lives in a shelter of his own, make sure that it is raised off the ground, has dry bedding and is insulated or heated. Make sure also that your pet has a constant source of clean water – not snow. Thermal heaters are available to make sure the water source doesn't freeze. If your dog spends a lot of time outdoors, especially if he's a working animal, feed him extra calories because it takes more energy in winter to keep body temperature regulated. Without proper care, cold weather can be dangerous to your pet.
For more information, please read the story How to Help Your Pets Weather the Cold Winter.