Malignant hyperthermia HP:0004896 SNOMEDCT_US:213026003 HP:0002047 Malignant hyperthermia is characterized by a rapid increase in temperature to 39-42 degrees C. Malignant hyperthermia may occur in response to either inhalational anesthetics such as halothane, to muscle relaxants such as succinylcholine, or to exercise. SNOMEDCT_US:405501007 UMLS:C0024591 Abnormality of temperature regulation