When warming pumped milk, avoid using bottle warmers as they often overheat the milk, which can destroy nutrients. Instead, place the bottle in a bowl of warm water for a minute or two, stirring occasionally. For a faster process, you can keep a thermos of warm water in the room or simply bring the refrigerated bottle to room temperature by taking it out of the fridge an hour before the expected feed time. If you choose to warm it, remember to use the milk within two hours of heating.