Based on the theory of Traditional Chinese Medicine (TCM), fever can be categorized into 2 groups – External causes and Internal causes.
When it comes to fever due to external causes, the ancient TCM classical book of Yellow Emperor’s Inner Classic (also known in Chinese as Huangdi Neijing), which dated thousands of years ago, has mentioned that almost all the common cold due to external factors are caused by coldness (temperature and weather).
It says that, “people who have cold, will feel hot (meaning fever).” In a nutshell, having fever during a course of common cold is an instinctual reaction in the way that our body is naturally getting rid of the cold in order to restore healthy balance.
At this time, we should assist body’s Yang Energy (warmth energy) so that it could do its job efficiently by pushing out the cold; we should NOT be using cold herbs (herbs with cold property) at this time because cold herbs will further damage the Yang Energy, making the warmth energy weaker, disabling its job, and in the end make the common cold worse. If you use too much cold herbs, you will eventually notice that the body will get weaker over time, you will frequently catch colds and symptoms will get worse each time.
Internal causes of fever are mainly due to poor diet, over-exertion, over-thinking which damage Spleen and Kidney’s Yang Energy. Once the Yang Energy becomes weaker, Yin Energy (cold energy) eventually becomes more dominant, and will push the warmth energy out of the body (to the surface) resulting in symptoms like feverish sensation, hot feeling on the palm and sole, feeling warm during sleep (ex, menopausal symptoms) and tidal fever (hot sensation that comes in wave).
At this time, we must “tonify”, “sink” or “re-direct” the Yang Energy back into the body. If we don’t do so, or even use cold herbs to “diminish” the fire, we will damage the Yang Energy even more and lead to many other health problems in the long run.