The three months of summer is the period of flourishing. Heaven-qi and Earth-qi have converged and all things are in bloom. People should go to sleep late in the night and get up early in the morning, avoiding being irritated by the longer, hot days and avoiding anxiety in life. Try to delight in life and enabling the qi to flow smoothly. Such an attitude toward life in summer is the outward manifestation of a cheerful state of mind. This is what adaption to Summer-qi means and this is the principle for health preservation. Violation of this rule may impair the heart and result in malaria in autumn and severe diseases in winter due to insufficient storing-up of supplies in autumn.

--The Yellow Emperor's Inner Classic (Huáng Dì Nèi Jīng)

Three months after the Start of Summer is the hottest season of the year. During this period, people must keep a balance between Heaven-qi and Earth-qi. Keep regular hours, sleep late in the night, get up early in the morning, and guard against conceit and rashness.

As it says in traditional Chinese medicine, “summer is associated with the heart, and the cultivation of the heart will be beneficial for growth”. The key principle of health preservation in summer is to nourish the heart and protect the yang qi. Hence, heath preservation after the Start of Summer should focus on the heart.

There are six solar terms in summer: Start of Summer, Grain Buds, Grain in Ear, Summer Solstice, Minor Heat, and Major Heat.