A patient with severe hypothermia presented with an initial rectal temperature of 28.3 degrees C coupled with a hemoglobin of 2.2 g x dL(-1) and acute pancreatitis. Although hypothermia decreases oxygen and substrate consumption by tissues and can be cerebro-protective, the ideal rewarming strategy is unclear when the oxygen-delivery system is profoundly deficient, as with severe anemia. In this patient, truncal active external rewarming with a forced-air system, heated inhalation, and slow warmed transfusion yielded a 1.5 degrees C x h(-1) rate of rewarming and a good outcome. We discuss the numerous protective and detrimental factors affecting oxygenation and ventilation during hypothermia coupled with profound anemia and the possible etiologic explanations for coexistent hypothermia and pancreatitis.