“Burner” or “warmer.” Any of three specific regions (collectively the San, or three Jiao) of the thorax and its organs: the Upper Jiao is the region above the diaphragm and includes the heart and lungs; the Middle Jiao is the region from the diaphragm to the navel and includes the spleen and stomach; and the Lower Jiao is the region from the navel to the upper border of the pubic bone and includes the liver and kidneys.