Malignant hyperthermia is a serious anesthetic complication, presenting with various manifestations, with high mortality and morbidity. There are several incomplete and abortive forms, and the clinicians must be aware of the possibility of malignant hyperthermia, and recognize the first signs of the hyperthermic crisis hyperthermia, hypermetabolism and muscular rigidity. Screening is performed by in vitro contracture testing on a muscular biopsy. Treatment is based on discontinuation of triggering agents and dantrolene administration, as well as supportive care. Cellular investigations demonstrate that the malignant hyperthermia crisis presents as an intracellular flooding with calcium, leading to an abnormal muscular contracture. Several mutations in particular involving the ryanodine receptor gene have been linked to malignant hyperthermia.