Anaesthetic management of the critically ill patient who requires operative intervention remains a significant challenge and source of anaesthetic mortality. The goal of the anaesthetist has always been to facilitate surgery (which is often potentially life-saving) in these patients but, in addition, choices and techniques chosen by the anaesthetist may have a significant effect on long term outcome. The anaesthetic management begins preoperatively by a careful assessment of the critically ill patient. Preoperative high risk consent must be taken from the patient or one of his close relatives. Transfer of the patient within the hospital must be safe and organized. Preanaesthetic warming appears to attenuate the redistributive hypothermia after anaesthetic induction and decrease the incidence of IPH.