Maintaining patient's temperature above 36 grades Celsius throughout the perioperative period is challenging. Thus, it is essential to monitor temperature in order to be able to take measures to avoid the appearance of hypothermia. Once the temperature has decreased, its treatment is difficult since the application of heat to the body surface takes a long time to reach the core thermal compartment. Intraoperative warming alone cannot avoid postoperative hypothermia. The application of forced-air warming system during the preoperative period has been shown to be the most effective measure to prevent hypothermia and maintain intraoperative normothermia. However, it would not be efficient to provide a long-time prewarming in short-term surgical procedures. Thus, the ideal warming time prior to the induction of anesthesia has long been investigated.
Due to the searching of optimal prewarming time and the lack of evidence about the efficiency of prewarming in patients submitted to transurethral resection, the conductance of this study is justified.