A 55-year-old man was scheduled to undergo revisional total hip arthroplasty under general anesthesia. During the operation, a warm blanket and fluid warmer were applied, with his body temperature maintained at 35℃, as assessed with the use of a temporal-artery thermometer. In the course of the operation, severe bleeding developed, which required a massive transfusion of packed red blood cells and other blood components to correct the electrolyte and pH balances; the infusion of cardiovascular drugs was also preformed. However, the hemodynamic status of the patient deteriorated to severe hypotension, with atrial fibrillation, non-sustaining paroxysmal ventricular tachycardia and ventricular fibrillation. The patient was re-evaluated, and it was realized the temporal-artery thermometer had been incorrectly monitored, causing hemodynamic deterioration, which was assessed as hypothermia from a nasopharyngeal temperature of 29 ℃. Active warming methods, including a condensed humidifier, and warming of the fluids and blood compounds with a rapid infusion system, were instigated, resulting in stabilization of the patient's hemodynamic status and the disappearance of his dysrhythmia.