Warming up breast milk

Natasha

I’m going on a trip in May and I’ll be leaving my son with my in laws for the weekend. He has no problem taking a bottle during the day and really doesn’t have a problem taking it at night. It just when he wakes up in the middle of the night it seems to take too long to warm up his milk. Does anyone know a fast and efficient way to warm up breast milk for those middle of the night feedings?