Overnight water can be drunk, but pay attention to the nature of the water with or without changes, if there is water quality abnormalities or odor and other abnormalities, then do not drink. 1. Overnight water, especially plain water, can be reheated and drunk if it is well preserved (refrigerator chilled, sealed, etc.) and there is no abnormal change. 2. If the water is not properly preserved, there are foreign substances in the water (such as dust, mosquitoes, etc.), and there are abnormal changes in the nature of the water (such as water from clear to cloudy, odor, etc.), you should not drink. Secondly, overnight water can have a large number of microbial reproduction, especially with sugar, juice powder and other substances in the water, also not recommended to drink, so as not to cause gastrointestinal discomfort after drinking. Overnight water can be drunk, but should pay attention to the proper preservation, the nature of the water has not changed, after drinking, if there is discomfort, should be immediately to the local hospital.