If there is no Sun, there is no life on earth. Same in your body, if there is no Yang Qi, the life will be end. Our body is just like a microcosm, our body vitalities depend on the Yang Qi normal function. So we have to protect and culture our Yang Qi in our daily life. This is why I always tell my patients not to drink cold or ice water, in order to protect spleen Yang Qi, always keep their back and feet warm, in order to protect Kidney Yang Qi, always keep their chest covered, in order to protect lung and heart Yang Qi, always try to be peace in mind, in order to protect the liver Yang Qi.
This concept has been mentioned thousands years ago in Chinese ancient medicine book, HuangDiNeiJin Chapter 3: 阳气者，若天与日，失其所则折寿而不彰. Even only one sentence in Chinese, It is very hard to translate in English, I will do my best to translate it for you: The yang qi of the body is like the Sun. If the Sun loses its brilliance, all things on Earth become inactive. The Sun is the ultimate yang for earth. This heavenly energy surrounds the Earth. And in the body, this means that the Yang Qi is like the Sun, circulates around the body and has the function of protecting the body, if body loses the Yang Qi, then the life will be shorter until it is over.
Over all, Yang Qi is just like the sun in the sky, send the light and keep our body warm, bright and function. Yang Qi is the main force to keep body energy, support body metabolism, keep Yin, blood, fluid move and maintain their normal function in human body, if no Yang Qi exists, life is stop. So start to protect your Yang Qi today.