It is better to drink green tea in summer. Because black tea is a hot substance, while green tea is a cool substance, the metabolism of human body is faster in summer, and it is easy to be invaded by hot air. Proper use of green tea can play the role of promoting fluid production to quench thirst, clearing heat and relieving summer heat. Moreover, green tea has high nutritional content, and also has medicinal values such as reducing blood fat and preventing arteriosclerosis. Drinking green tea in summer can eliminate calories, reduce calories and enhance human body resistance, which is more suitable for people with strong body heat and stomach and full of energy. It is also possible to drink a small amount of black tea in daily life in summer, but a large amount of black tea may cause excessive internal heat. It is suggested that patients should also control their drinking amount reasonably and keep it within 500ml per day.