After the breastmilk has been expressed and placed at room temperature, it can be heated by warm water or a milk warmer when feeding. 1. Warm water heating: the temperature of warm water should be controlled at 40 ~ 50 ℃, breastmilk can be placed in special bottles or milk storage bags in the water heating, be careful to shake the container so that breastmilk heated uniformly, in addition to pay attention to do not use the boiling water heating, which will destroy the nutrients in the breastmilk. 2. Milk warmer heating: Adjust the temperature of the milk warmer to 40 ℃ and heat it under water. In addition, expressed breastmilk should not be heated in a microwave oven, because the microwave oven may destroy the nutrients in the breastmilk. Parents are advised to use the correct method to heat breastmilk to avoid the destruction of nutrients or deterioration of breastmilk, etc. If the baby has abdominal pain or diarrhea after drinking heated breastmilk, it is recommended to consult a doctor in time, and under the guidance of the doctor, the cause of the illness will be clarified and then treated according to the symptoms.