The temperature a dog can withstand will depend on different factors. If your dog has a lot of thick fur, he or she may be able to stay outside longer. However, if your dog has short hair or not much hair at all, you won't want to leave him or her in the cold.
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Dogs can handle colder temperatures better than human's, well most breads. The dogs with a lot of hair have an advantage in colder weather. If the temperature is freezing out, I would say its too cold for any animal to be outside for long periods of time, especially when the sun is not out.
Sled dogs (also sledge dogs and sleigh dogs) are a group of dog breeds and mongrels that, historically, were bred for the purpose of pulling a dog sled. These dog sleds were important for transportation...