The most common sign in early stages who are at risk at malignant hyperthermia is tachycardia. It is because a person who is at risk for malignant hyperthermia, they usually experience symptoms that are associated with the heart and muscles where tachycardia is one of the symptoms for it is classified as cardiovascular problem, and the reason for it to be marked as an early sign because of its ability to provide nervous stimulation that could lead to harmful complications.