Hyperthermia or heat stroke corresponds to an increase of body temperature due to the body's inability to control excess heat to which it is subjected. It is called malignant hyperthermia when the body temperature exceeds 104°F. It can be triggered by a very intense physical effort, by exposure to excessive heat, or in response to certain drugs. Malignant hyperthermia is triggered in susceptible individuals by certain anesthetics used in surgery. In malignant hyperthermia, the body is hot, the muscles are contracted, the heart beats very fast, and heart disorders can be triggered, for which urgent care is required through hydration and cooling the body.