This review considers several recent concepts regarding aetiology and treatment of accidental hypothermia. The importance and effectiveness of shivering heat production in the attenuation and reversal of hypothermia is described. Immediately following removal from cold stress, the patient is in danger of a deteriorating condition that may be due to collapse of arterial pressure and/or continued decrease of core temperature. Several controversies are discussed. It is advised that, when possible, patients should be actively but gently warmed as soon as possible (especially if arrival at the emergency department will take greater than 45 min). Extra time should be taken to check for life signs before cardiopulmonary resuscitation is initiated. Chest compressions should proceed at regular normothermic rates and care should be taken to not overventilate the patient. In the emergency department, several factors should be considered before deciding on a treatment regimen. These factors include level of consciousness, cardiovascular stability, core temperature and the direction of change of core temperature. It may be advantageous to transport the more severely hypothermic patient to a more advanced care facility even though transport time may be greater.