Malignant Hyperthermia By David Tanen, MD, David Geffen School of Medicine at UCLA Reviewed / Revised Mar 2023 View Patient Education Pathophysiology Symptoms and Signs Diagnosis Treatment Prevention Key Points Malignant hyperthermia is a life-threatening elevation in body temperature usually resulting from a hypermetabolic response to concurrent use of a depolarizing muscle relaxant and a potent, volatile inhalational general anesthetic.