The formula milk powder can be brewed for a long time with the ambient temperature, storage containers, need to be analyzed on a case-by-case basis, can not be generalized. After the formula is brewed, if it is left for too long, it will easily breed and multiply various microorganisms, resulting in the deterioration of the formula. So it is advisable to consume the formula as soon as possible after it is brewed. In general, it is not recommended to drink formula after 2 hours of brewing in room temperature environment. If it is left undrunk, it is recommended that it should not exceed 1 hour at room temperature. If it is put into the refrigerator for refrigeration or freezing, it is recommended to use a well-sealed milk storage tool to avoid the growth of bacteria due to the large amount of food in the refrigerator. If your baby consumes formula that has been contaminated with bacteria or has deteriorated, he or she may experience diarrhea, abdominal pain, vomiting, abnormal crying and other manifestations. In addition, during formula feeding, pay attention to the timely cleaning and disinfection of bottles and teats. Usually control the feeding time and the amount of formula, and try not to leave it on the shelf; at the same time, you need to ensure the appropriate temperature when feeding, not too hot or too cold.