[Non-therapeutic intraoperative hypothermia: prevention and treatment (part II)].

General and regional anesthesia alter the physiological mechanisms of thermoregulation, and unintentional intraoperative hypothermia develops during most surgical procedures that last more than 1 hour. Monitoring of central temperatures among other vital signs is advisable in such interventions in order to detect temperature changes and check the efficacy of measures to prevent or treat hypothermia. Passive insulation reduces heat loss through the skin but most patients require active warming to maintain a normal temperature. Various skin surface warming systems prevent hypothermia from developing and provide effective warming. The most often used are forced-air or warm water circulation devices. When large volumes of fluids must be infused intravenously, they must be warmed to body temperature to avoid heat loss.