We store our baby’s formula and refrigerate it premixed in the bottle. When baby needs a bottle, we warm a bottle in heated water in a kettle. If it isn’t suggested to feed a baby the formula if it is lower than room temp, what are ways I can warm it? Sometimes we aren’t going to family’s or friends’ house. We use Similac Advance powder and it is good for 1 hour after first feeding from the bottle. We carry the refrigerated bottles in the bag with the ice packs provided with the diaper and supply bag. Thanks in advance for your suggestions!!