What temperature is too cold for dogs?

Dogs can tolerate temperatures as low as -4℃. Anything below that and they will lose body heat fast and get distressed. Also, dogs with double-coated fur can withstand cold temperatures better.

Why does my dog sleep on its back?

As weird and funny this sleeping position looks, it helps your pooch to cool down. Dogs sweat through the hairless parts of the skin. Since the belly has minimal hair, sleeping with the belly up is a quick cooling mechanism.