CC Hypothermia is frequently encountered during major operations despite many efforts to prevent this complication. Numer ous reports have identified the adverse effects of hypo thermia including coagulopathy, acidosis, alterations in response to pharmacological agents, detrimental cardiac arrhythmias, and a mortality rate of near 100% for cases with a core body temperatures of 32 o C [1,2]. Therefore, a variety of devices have been developed to achieve rapid fluid warming and infusion because prevention of hypothermia via intravenous infusion of warm fluid is probably the most cost effective intervention, particularly for circumstances in which large volumes of fluid are required. However, after the utilization of the rapid infusion system (RIS) in liver transplantation (LT) recipients, we noticed a considerably lower intraoperative body temperature (BT) compared to the recipients before RIS. Therefore, in this study, we aimed to compare the BTs of LT recipients before and after receiving RIS. Medical records of adult patients who underwent first LT were reviewed. Twenty-three recipients were divided into nonRIS (n = 12) and RIS (n = 11) groups. The exclusion criteria in cluded patients with model for end-stage liver disease score less than 9 or greater than 25, total input greater than 20 L, and RIS infusion less than 4 L. After induction, either RIS (Haemonetics Corp., Braintree, MA, USA) or Level 1 (Level 1 Technologies, Rockland, MA, USA) was connected to the Advanced Venous Access catheter (Edwards Lifesciences LLC, Irvine, CA, USA) placed in the right internal jugular vein. For external methods of warming and body temperature preservation, a water circulating heating mattress was used and the extremities were insulated with cotton rolls and vinyl covers. The operating room tempera