We do not recommend using a microwave to warm up baby's food or drinks. Microwaves might alter the quality of food/drinks and destroy some valuable nutrients. Furthermore, microwaves do not heat evenly and they might leave “hot spots” that would not be noticeable to you but that could scald your baby. When heating up liquid or food in the microwave, please only place the container without screw ring, teat and cap. Always stir heated food to ensure even heat distribution and check the temperature before serving.