DDs have been interested in bringing hot lunches in their thermoses and I've just been jamming them into their planetbox lunch bags (not ideal) along with an ice pack for their yogurt, cheese, fruit, etc. But I don't think it's working - the ice pack cools the thermos down so that the food is only lukewarm by lunchtime. How do you pack lunches where you have both a hot a cold component? Or do you just not? I almost feel like I need to get different lunch bags for hot lunches vs. planetbox lunches...