Figure 1. Overall heat balance was near 0 before induction of anesthesia but subsequently decreased [nearly equal] 31 kcal/h. Changes in body heat content (Delta Q) were calculated two ways: (1)“overall” heat balance was calculated from the difference between metabolic heat production and heat loss, and (2)“extremity and core” changes were calculated as the sum of measured changes in the arms and legs and the change in core temperature multiplied by the weight of the trunk and the specific heat of human tissues. Body heat content, calculated both ways, was significantly less at all times after induction of anesthesia than during the control period. Body heat content results are presented as cumulative changes, referenced to induction of general anesthesia at elapsed time 0.