In Australia the single most important factor influencing the incidence of SIDS is the climate. The incidence in mid summer in South Australia is 0.7 per 1,000 live births, in mid winter in Tasmania it is 6.3 per 1,000 live births. It is predicted that if infants under 6 months of age in cold weather were tied into swaddling and placed supine to sleep as in Asia and Czechoslovakia, and older infants who may object to restriction of movement, had the cot made up with the infants' feet touching the lower end, warm clothing and no more than a single thin porous cover, the incidence of SIDS as in Asia and Czechoslovakia could be reduced to less than 1.0 per 1,000.