Using infrared thermography, the changes in the surface temperatures of the tracheal tube between the tip and 15 cm from the proximal end are measured following dipping into 60°C water for 3 minutes. Infrared thermographs show the changes in the surface temperature after 5 minutes of the Mallinckrodt Nasal RAE Tube (a) and the Portex North Polar Preformed Tube (b) after withdrawing the tube from 60°C water. Color bars represent the temperature scale ranging from 20 to 60°C.