You've got it in the bag! This carry-all tote has a patented, attached gel liner that stays cold when frozen. There's no need for a separate insert--just store the whole bag in your freezer until you're ready to put items in it, and go! From PackIt.
Gel-lined walls chill a large meal or salad, a snack and a 12oz (340ml drink for up to 10 hours (depending on external temperatures
Folds flat and freezes overnight (12 hours
Includes shoulder strap
Roomy design fits extra-large containers
Storage pouch holds utensils and personal items