To know exactly how cold it is, including the wind chill factor. A kennel is good to have but can not protect from frostbite on their extremities. Do not forget to bring your pet to the shelter from the cold. Post a warm blanket to sleep, because the tiles can be chilly. You can also buy the beds are made for dogs at your local pet store.
Another misconception is that snow is a substitute for fresh water. Make sure your pet always has fresh water available to drink, regardless of weather conditions.