Malignant hyperthermia (MH) is a devastating condition that occurs during general anesthesia. We report a patient with a type A dissecting aortic aneurysm (DAA) who underwent ascending aorta grafting plus hemiarch replacement. MH was highly suspected according to the patient's hypercatabolic state and hemodynamic instability during the rewarming process following a cardiopulmonary bypass (CPB). Although cases of MH during cardiac surgery have been reported in the literature, there is a very limited number of case reports relevant to aortic surgery, deep hypothermia, and subsequent genetic study.