Many believe that the consequence of hypothermia is an orderly decrease in metabolism. However, oxygen consumption is increased, except when anesthetics and neuromuscular blocking agents are used to block the thermoregulatory response. This may be detrimental in patients with a bleeding diathesis as a result of the impairment of platelet function, activation of the fibrinolytic cascade, and inhibition of clotting enzyme kinetics that are associated with cooling of the blood. To date, a potential benefit of hypothermia in trauma patients has not been identified. Based on current data, every attempt should be made to prevent heat loss from occurring and to aggressively treat hypothermia once it has occurred.