Theoretically, heating is not necessary.…Whether it's room temperature milk or pasteurized milk, you don't need to heat it either. But if someone prefers hot milk, you can heat it for about 30 seconds in the microwave.Just use the microwave.No need to boil it!Don't think that boiling will sterilize it!Room temperature milk has already been flash-sterilized during processing, so there's no need for manual sterilization.