The Chinese medical classic Huang Di Nei Jing Su Wen 2 advises us in our conduct specific to the summer season:
"The three months of summer...denote opulence and blossoming. The qi of the heaven and earth interact and the myriad beings bloom and bear fruit. Go to rest late at night and rise early. Never get enough of the sun. Let the mind have no anger. Stimulate beauty and have your elegance perfected. Cause the qi to flow away, as if that what you loved were located outside. This corresponds with the qi of summer and it is the Way to nourish growth. Opposing it harms the heart."
Chinese medicine advises that our daily habits should shift with the season. Summer, being more yang, expanding, more outer, more bright inspires our actions and attitude to follow suit. With extra daylight, we rise a little earlier, go to bed a little later. We spend more time out to enjoy the sun. The garden is in bloom, so we relax outside and enjoy the environment, admire the beauty. The Nei Jing gives us a medical prescription to relish in it.
But what if we have an underlying deficient yin condition already causing heat, dryness or overactivity? What if we have constitutionally excess yang, manifesting as headache, insomnia, or irritability? This is when we must have "our elegance perfected" and let "the mind have no anger."
Keep it flowing and don't overdo it in the heat and sun, especially if you know you have constitutional or pathogenic heat. Enjoy the "opulence and blossoming" of the summer, but don't forget to protect the yin!