Dogs, as a general rule, love the great outdoors and the winter is no exception. To properly determine how long your pet should stay outside in cold temperatures, a number of factors need to be taken into account. These include breed, coat type, general health, and age of your dog; whether he/she has been acclimated to the colder weather; the availability of shelter; as well as individual differences in the desire to spend time outdoors. Smaller, short-coated, ill, or geriatric dogs have less tolerance for the cold and therefore are limited to the time they may be able to spend outdoors.
Certain breeds, such as the northern breeds (husky, etc), may actually prefer extended periods outside in the colder weather. If this is done, ensure that adequate shelter is available and that they have been acclimated to the colder weather. Shelter should be an insulated dog house, off the ground with the door protected or facing away from the prevailing wind and some straw or a blanket for the dog to burrow into. Dogs rely on their body heat to warm their immediate environment, so an appropriate shelter should only be large enough for them to lay down comfortably.