Cool September 17 2014
To counteract heat in the system or skin; as usually indicated by redness, soreness, and feelings of warmth.
The action of cooling slows down chaotic movement of Qi and other substances such as blood. It also removes soreness associated with excessive heat. This gives it a generally calming effect as well; and removes redness in the skin.
Cooling herbs are necessarily Yin in nature, as it is this quality which balances out the heat (an expression of Yang) by neutralizing it with its opposite.