Forty-five lightly anesthetized, paralyzed patients having intra-abdominal or extra-abdominal surgery were studied. Significant linear correlations were found between the patients' esophageal temperatures and their operating room temperatures at intervals of one, two, and three hours after induction of anesthesia. In addition, operating rooms could be classified by their effect on patients' temperatures: (1) rooms below 21 C in which all patients became hypothermic; (2) 21 to 24 C (70 to 75 F) rooms in which 70% of the patients remained normothermic and 30% became hypothermic; and (3) 24 to 26 C (75 to 79 F) rooms in which all patients remained normothermic. Operative site (intra-abdominal versus extraabdominal), anesthetic agent utilized (ether, halothane, or methoxyflurane, or a narcotic), and patient age did not significantly influence the effect of environmental temperatures on patients' body temperatures.
Morris RH. Operating Room Temperature and the Anesthetized, Paralyzed Patient. Arch Surg. 1971;102(2):95-97. doi:10.1001/archsurg.1971.01350020005002