Moxibustion is a technique that involves the burning of Chinese Mugwort to facilitate healing.  It was discovered long ago that unlike other herbs which if placed on a piece of wood burn in an outward direction, moxa burns primarily downward. The heat penetrates deeply into the body, strengthening the immune system, expelling cold from deep in the body, and warming the meridians, which leads to smoother flow of blood and qi and pain relief.  Moxa can be applied directly or indirectly.