According to some scholars, the expression comes from Down Under. Cowboys spend a lot of their time outdoors looking after animals. During cold winter nights when the temperature dips, the men often cuddle up with their dogs to keep warm. When it is slightly cold, they need the body heat of only one animal to keep warm; such a night is referred to as `one dog night’. When it becomes extremely cold, the men may need three dogs to keep warm. Such an extremely cold night is referred to as `three dog night’. This practice of embracing dogs for body warmth was quite common among the Australian Aborigines.
*Take extra blankets. According to the forecast, it’s going to be a three dog night.
`Three Dog Night’ is also the name of an American rock and roll band. They were quite popular in the late 1960s and early 1970s.