This may be a silly question 😅

My son is on whole milk already, I’m wondering how you mommas take milk to go when traveling or going out with baby? How long can whole milk sit out at room temp?

He still drinks about 3-4, 5oz. bottles a day. Since transitioning him to whole milk it seems like he likes it and wants it more. I use the tommee tippee travel bottle (picture) could I just fill that with room temp milk and take it to go? Or put boiling water in there and take separate bottle filled with milk and just warm when I need it?