A brief review about the effects of hypothermia is presented, with regards to the difference between accidental hypothermia and controlled mild hypothermia (Core temperature = 33-35 degrees C). Mild hypothermia does not seem to affect the cardiac performance, while recent experimental reports show potential protective effects on the cardiac muscle during acute infarction. Mild hypothermia improve the outcome of brain function after cardiac arrest and head injury, while experimental reports show a potential protective effect of local spinal cord cooling during ischemic injury. Induced hypothermia of single organ is widely applied in liver resection and in other surgical procedures, further the cardiac ones. In the acute respiratory failure, mild hypothermia may induce a decrease in PaCO2, in sedated and muscle relaxed patients, due to the decrease of metabolic demand. In this setting a mild induced hypothermia potentially may decrease the side effects of therapeutic hypoventilation (permissive hypercapnia) both on haemodynamics and brain circulation. Preliminary data are presented about five ALI/ARDS patients, enclosed in a randomized trial, who were mechanically ventilated and cooled with an air-sheet: three patients died because of underlying disease and two patients survived with complete recovery. Mild controlled hypothermia seems to provide new interesting clinic uses.