Whether it is bad or not depends on what kind of water you choose to drink: 1. Drink clean water, that is, water that is not polluted by industrial waste and domestic waste. 2. After drinking cold boiled water, it is found that after the boiled water is naturally cooled, the chlorine in the water is reduced by 5% compared with ordinary natural water, and its biological activity is 4-5 times higher than that of natural water, which is very similar to the water in human cells, so it is easy to penetrate the cell membrane and be absorbed by the human body. It is best to drink natural mineral water containing a lot of trace elements and minerals. The second is how much water to drink. The international nutrition community proposes to drink 8 glasses of water every day, each with 250 ml. For people with a balanced diet, drinking 8 cups of boiled water and mineral water is the most ideal. Of course, drinking water can also be replaced by other drinks, but the choice should meet personal needs. For example, dieters can drink more drinks to supplement their physical strength, and children and women should drink more milk. Only high-sugar drinks are not suitable for long-term drinking. The third is how to replenish water. 1, don't wait for thirst to drink water. Thirst indicates a lack of water in the body. Get into the habit of drinking water often even if your mouth is not thirsty. In addition, according to the current internationally respected method, it is to drink 200-300 ml every morning, 200-300 ml two hours after meals and half an hour before going to bed, and 600-800 ml the rest of the day. Generally, warm water is appropriate. Drinking 1000- 1500 ml every day can meet the needs of the body.

The following five kinds of water are not suitable for drinking, which will bring certain harm to the body: first, water boiled in the stove for a night or a long time; The second is to put warm water in a thermos for several days; Third, the residual water after repeated boiling, especially the water in the boiler; The fourth is the boiling water that is boiled or not boiled every other day in the boiling water pot; The fifth kind is the "urn foot water" after steaming rice and meat. Because nitrite in boiled water is easy to increase, it is a potential hazard to human health.