DD was EBF the first year so I never had to carry bottles with me when we are out and about. I just whip out the boob. Now that she's on WCM, should I carry milk with me? Right now I just carry water with me and feed her snacks and whatever we eat but we are never out for more than a few hours at a time so we wait until we are home for milk. But what if we are out ALL day? How long is cows milk good at room temperature? And how long do you keep milk in your sippy if she doesn't finish it? What do you guys do?