Correlation Between Core Temperature and Skin Temperature Measured by 3M SpotOn

Core temperature should be monitored under general anesthesia. Recently developed 3M Spoton skin temeprature which is applied on temporal artery is correlated with core temperature measure by esophageal prove in several studies. Conventional skin temperature over carotid artery is also correlated with core temperature in several studies. The purpose of this study is comparing 3 methods of temperature monitoring. First, conventional core temperature measure by esophageal stethoscope. Second, 3M Spoton applying on temporal artery. Third, 3M Spoton applying on carotid artery