Heat balance during surgery involving body cavities

Three groups of adult patients were anaesthetized for elective intra-abdominal surgery. In one group, patients were ventilated with dry anaesthetic gases, and these patients all lost heat. In the second group humidification was used to annul respiratory heat exchange, and these patients lost heat initially but tended to regain heat during anaesthesia. The third group, in addition to humidification, had surface insulation and all these patients gained heat. It is suggested that conservative methods which negate heat loss are able to prevent hypothermia by the retention of metabolically produced heat.