The growing use of cold hypothermia for organ preservation and human surgery has generated an urgent need for a basic understanding of the effects of cold on tissues and of the adaptive responses of endothermic animals. Mammalian hibernation provides here a valuable frame of reference. The approach used in this international meeting has been widely inter-disciplinary. The fields covered range from the molecular biology of adaptation to the eco-physiological responses to cold and food scarcity, via cold effects on membrane and enzyme function, mechanisms of heat generation and metabolic regulation. Applications to human surgical hypothermia, organ preservation and seasonal affective disorders have been duly examined. Unexpectedly, the interest in hibernation has proven to go far beyond the effects of cold. In many respects, it involves an exaggeration of the amplitude of biological cycles. At the cell and molecular levels, control systems operate over a wider range, bringing to light factors hitherto largely ignored.