This is probably a dumb question but what do you do with bringing an extra formula bottle when you are out for several hours running errands? I read on the box it goes bad after an hour or two. I am currently pumping and Bm stays good for 6 hrs so I have no problem throwing a bottle or two in a bag and going out for the day. Do you just put it in a freezer pack or something? I'm trying to wean and give some formula bottles bc I just can't handle pumping and working full time!