Mainly eat light, refreshing and appetite-stimulating foods. When preparing meals, pay attention to the color, aroma and taste of the food to increase appetite. 2. When making dishes, adding an appropriate amount of vinegar can not only increase the flavor, but also protect vitamin C, sterilize and increase appetite. 3. It is of great benefit to drink some porridge at breakfast and dinner. This can not only produce fluid and quench thirst, cool and relieve heat, but also nourish the body. 4. The elderly should also pay attention to eating less and no greasy food in summer, and eat more light and clean food. For the frail elderly, they should avoid eating cold drinks and raw and cold fruits to avoid digestive dysfunction and illness. 5. Drinking beverages cannot replace drinking water. Because most drinks contain a certain amount of sugar, the higher the sugar content in the drink, the higher the osmotic pressure, and the less likely it is to be absorbed by the cells. Instead, it will take away the water in the cells and easily cause water loss in the body. In addition, it is often difficult to quench thirst with cold drinks, leading to frequent overeating, which is a strong cold stimulus to the digestive tract, causing abnormal peristalsis and functional disorders of the digestive tract, leading to abdominal pain, diarrhea, etc. 6. The knowledge of drinking water: Don’t wait until you are thirsty to drink water: Many people’s living habits are to decide whether to drink water based on whether they are thirsty or not. In fact, this is unscientific. Because thirst indicates that the body's water balance has been lost and the cells are beginning to become dehydrated. It is too late to drink water at this time. It is easy to drink too much if you are very thirsty: When people are very thirsty, they are most likely to drink too much water at one time, which makes it difficult for the stomach to adapt and causes adverse consequences. The ancients advocated "drink without being extremely thirsty, and don't drink too much", which is a scientific method to prevent being thirsty and not choosing to drink. If you are extremely thirsty and unbearable, you should drink water slowly to avoid physical harm. It is not advisable to drink too much water before going to bed, because when a person is asleep, the human body only maintains basal metabolism, and all metabolisms proceed very slowly, without the need for too much water. Moreover, drinking too much water before going to bed is not conducive to a night's rest. It is not advisable to drink water during meals, because drinking water during meals will dilute the digestive juices, which is not conducive to the digestion and absorption of food, and will be detrimental to the body in the long run. Drinking water in the morning is good for health: drinking water in the morning can replenish the water consumed overnight, reduce blood concentration, promote blood circulation, and maintain normal levels of body fluids. It is best to drink mineral water: because mineral water does not contain sugar and has no irritating effect, it is not irritating like some drinks, nor does it contain a lot of sugar like fruit drinks. In some developed countries, people regard mineral water as the best health drink. 7. Maintaining an indifferent and peaceful state of mind is extremely important for health preservation in summer. You should be refreshed, broad-minded, and calm in your thoughts to avoid inner fire. 8. In summer, the king of fire is in season, the sky is hot and the earth is hot, and the warm and hot Qi is strong. People should go to bed late and get up early, follow nature and maintain Yang Qi. 9. The climate in summer is hot and takes a heavy toll on the human body. Exercising in the sun for a long time may cause heatstroke.