Malignant hyperthermia (MH) is a hypermetabolic syndrome with variable presentation that may be determined by genetic susceptibility of the patient, dose and duration of pharmacological triggering agents and environmental stress factors. The presentation may be accelerated or attenuated by concurrently administered drugs. 1 ,2 We report a case of intraoperative MH which presented toward the end of a six-hour procedure for correction of scoliosis in a patient with multiple previous exposures to triggering agents. In addition to a number of potential pharmacological triggers, stress associated with light anaesthesia and a 'wake-up test' may have contributed to the eventual fulminant presentation of the clinical syndrome. CASE REPORT History and examination A 28-year-old, 36-kilogram female (ASA physical status 11) was admitted for elective surgical correction of congenital idiopathic scoliosis. There was no family history of anaesthetic problems. The patient gave a history of nine previous uneventful anaesthetics in this and other hospitals, although retrospective study of the casenotes suggests otherwise. A summary of the procedures and agents to which the patient was exposed is listed in Table 1. Postoperative temperatures varied from 37.6°C to 38.S°C.