In order to improve our understanding of the evidence-based literature supporting temperature management during adult cardiopulmonary bypass, The Society of Thoracic Surgeons, the Society of Cardiovascular Anesthesiology and the American Society of ExtraCorporeal Technology tasked the authors to conduct a review of the peer-reviewed literature, including: 1) optimal site for temperature monitoring, 2) avoidance of hyperthermia, 3) peak cooling temperature gradient and cooling rate, and 4) peak warming temperature gradient and rewarming rate. Authors adopted the American College of Cardiology/American Heart Association method for development clinical practice guidelines, and arrived at the following recommendations: Class I Recommendations a) The oxygenator arterial outlet blood temperature is recommended to be utilized as a surrogate for cerebral temperature measurement during CPB. (Class I, Level C) b) To monitor cerebral perfusate temperature during warming, it should be assumed that the oxygenator arterial outlet blood temperature under-estimates cerebral perfusate temperature. (Class I, Level C) c) Surgical teams should limit arterial outlet blood temperature to <37 degrees C to avoid cerebral hyperthermia. (Class 1, Level C) d) Temperature gradients between the arterial outlet and venous inflow on the oxygenator during CPB cooling should not exceed 10 degrees C to avoid generation of gaseous emboli. (Class 1, Level C) e) Temperature gradients between the arterial outlet and venous inflow on the oxygenator during CPB rewarming should not exceed 10 degrees C to avoid outgassing when blood is returned to the patient. (Class 1, Level C) Class IIa Recommendations a) Pulmonary artery or nasopharyngeal temperature recording is reasonable for weaning and immediate post-bypass temperature measurement. (Class IIa, Level C) b) Rewarming when arterial blood outlet temperature >= 30 degrees C: i. To achieve the desired temperature for separation from bypass, it is reasonable to maintain a temperature gradient between arterial outlet temperature and the venous inflow of <= 4 degrees C. (Class IIa, Level B) ii. To achieve the desired temperature for separation from bypass, it is reasonable to maintain a rewarming rate <= 0.5 degrees C/min. (Class IIa, Level B) c) Rewarming when arterial blood outlet temperature <30 degrees C: To achieve the desired temperature for separation from bypass, it is reasonable to maintain a maximal gradient of 10 degrees C between arterial outlet temperature and venous inflow. (Class IIa, Level C) No Recommendation No recommendation for a guideline is provided concerning optimal temperature for weaning from CPB due to insufficient published evidence. (C) 2015 by The Society of Thoracic Surgeons, Elsevier, and the American Society of ExtraCorporeal Technology