I know that this is a hard question to get answered, and maybe nobody will have an answer. But I was planning on going to a picnic with my friends and bringing baby along with my pumped milk in bottles. How do I warm up the milk? There won't be a stove, and I've had trouble in the past warming up milk under the faucet. It never gets warm enough! And he hates cold milk. What do you think I should do?