Malignant hyperthermia (MH) is a life-threatening hypermetabolic disorder triggered by volatile anesthetics and/or succinylcholine. We report a case of a 58-year-old patient with a type-A aortic dissection. After induction of general anesthesia, a hypermetabolic reaction was successfully treated by deep hypothermia using cardiopulmonary bypass. Dantrolene became available in theater after the hypermetabolism was already treated successfully by hypothermia. Because of a low suspicion of MH, dantrolene was not administered when it became available. The patient fully recovered, and MH susceptibility was confirmed. Cardiopulmonary bypass should be considered to treat MH in case dantrolene and conservative therapy are unavailable or insufficient.