We traveled to Jost in April with a 24pack Polar Bear carry on cooler for the first time. Our flight was delayed TWICE! We didnt get to our destination on time. Everything was nice a frozen. We packed chicken, fish, cookie dough, spaghetti sauce and bacon. We used the blue ice paper from suggestions here on TTOL. They didnt open our bag at customs, just charged us 10.00. They did open the bag in Indy when we departed. Good luck