Three Dog Night

I was driving to work the other day and heard a radio announcer talking about a three dog night which is a colloquial saying for a very cold night.  But do you know where this saying originates?  It comes for Australia’s aboriginal people.  Aborigines (native Australians) sleep under the stars in a lean-to which is simply a sheet or sheets of plywood or tin roof leaned against a tree.  This lean-to provides a rudimentary cover from the elements and from the cold of the austral Winter night which can be quite cold in certain areas.  So where do the dogs come into all this?  The aborigines also raise numerous dogs even dingoes in their settlements and often sleep with them for warmth in their lean-tos.  A three dog night is such a cold night that an aborigine needs three dogs in his lean-to to keep him warm.