Some present with hard nodules and pain; in severe cases, it resembles a carbuncle (Yong, 痈). Upon sensation, wash with cold water and apply cold stones for moxibustion-like warming (Wen, 熨); in mild cases, it dissipates after a short while; in severe cases, continuous washing with water over several days is required until recovery. There is no limit to the number of washes, provided that recovery is achieved. If it does not heal, take a whetstone, heat it by fire until red-hot, and throw the stone into vinegar (Ku Jiu, 苦酒),