When you think of testing for malignant hyperthermia, you probably think of the pre-operative interview. It's standard to ask the patient about her history with anesthesia, follow with some questions about the family's experiences with anesthesia and determine whether there is a family history of unusual muscle disorders or malignant hyperthermia syndrome. This may catch the most obvious red flags, but for practical purposes, it's really not that effective for predicting a patient's risk for developing MH. Even patients who have low risk factors may later present with an MH episode.