Repeated heating of water is harmful. Chemicals such as nitrite will be produced in such water. Long term drinking will cause nausea, vomiting and other uncomfortable reactions, affecting health. Therefore, the boiled water boiled on the same day should be drunk on the same day, and can not be heated or drunk after the next night.
For the sake of convenience or saving water, some people often continue to heat the unfinished boiled water, which is a wrong practice. Repeated heating of water is harmful and will produce some chemicals harmful to the human body, such as nitrite. Long term drinking will lead to the inability of human red blood cells to carry oxygen and discomfort reactions such as nausea and vomiting.
Generally speaking, it's best to drink the boiled water on the same day, and the storage time should not be too long, especially in summer. At this time, the temperature is high, the bacteria multiply faster, and it will become raw water. After drinking, it may cause diarrhea, so we need to pay attention.
Boiling water can kill bacteria and remove harmful substances from human body. Most tap water is chlorinated when the temperature is as high as 100 deg; The chlorine content will be reduced when boiling. It will drop rapidly after boiling. It is recommended to boil it once and then drink it. Do not continue heating.