Today my son had to take some popsicles to school. My wife had them all frozen - the little juicy ones in their own bags that you have to rip open with your teeth. My son being a sharp 8 year old asked that she put them in a bag to preserve the cold. The bag just has an extra lining that looks like foil inside, so that they can stay cold on the ride to school.
However, my sharp son reasoned that if this was a bag that preserves cold, he felt that he was carrying his own personal refrigerator. So instead of giving the load to his teacher to put in the freezer, he kept the bag next to him in class all day.
Finally when it came time to enjoy their treats, he produced is bag of melted popsicles.