Moxibustion is the physical partner ( yin ) of the more energetic ( yang ) acupuncture needle. We can look at moxa having a more systemic effect on the physical body such as the bodies immune and defensive mechanism. The needle, on the other hand, is less physical and more energetic in its function. Of course, both of these modalities are interchangeable. If you are an acupuncturist reading this, then yes, the needle can be used in a more physical way, as indeed moxa can be used energetically. However, this is one of the paradoxes of Yin and Yang theory, it is both right and wrong at the same time!
Moxibustion is especially very effective if it is burnt directly on the skin as the body will benefit from the absorption of various natural oils- and of course the actual stimulus of heat. Small moxa cones known as chinetsukyu 知熱灸 are neatly rolled by the practitioner before being placed on the skin. They are removed just when they become hot and do not leave any burn. The combination of the heat and smell of the moxa is a very pleasant and rejuvenating experience.
Moxibustion has a very strong effect on the immune and defensive mechanisms increasing both red and white blood counts- the effects of which have been shown to last over a long period of time. It also regulates the acid-alkali balance, cholesterol, gastrointestinal and liver functions to name but a few. It has recently been used in Africa to treat TB in seriously immune-compromised patients.