The time to heat breastmilk in 45 degree water is variable, depending on the amount of breastmilk, its original state and how it is stored. For frozen breastmilk, it usually needs to be thawed and heated to a suitable temperature for feeding your baby. If the breastmilk is at room temperature or frozen, you can soak the container with breastmilk in 45 degree water and keep stirring the breastmilk during the soaking process to make it evenly heated, which takes about 5-10 minutes. If breast milk is frozen, it should first be soaked in room temperature water or lower temperature water through the sealing device, and then gradually add 45 degree water until the breast milk is completely thawed and gradually warmed up, usually for a longer period of time, increasing the water temperature helps to reduce the heating time, but exceeding 56 degrees may destroy the original nutrients in the breast milk. Frozen breastmilk can also be placed in the freezer until it slowly thaws, and then heated with water at 45 degrees like frozen breastmilk. 45 degrees water heated for more than 20 minutes will destroy the whey protein and other nutrients in breastmilk, so it should not be heated for too long. In addition, you should avoid using microwave oven or open fire to heat breast milk, and be clear about the time point when storing breast milk to avoid your baby from drinking expired breast milk. To prevent the high temperature from damaging the baby’s oral mucosa, test the temperature by dropping it on your arm before giving your baby heated milk, and feed your baby when it is appropriate. In order to avoid nutrient loss of breast milk, it is better to drink the heated breast milk within one hour, and the remaining breast milk should be poured out, not to mention frozen again, so that your baby will not drink spoiled breast milk.