It's a scientifically authenticated proposition: Rice Krispie treats are an effective insulator! The website My Science Project subjected their sweet device to rigorous testing and was impressed:
The Rice Krispies performed admirably, better than one of the best can cozies we tested. They work well as an insulating material because each individual grain of crisped rice traps multiple pockets of air. And when the Rice Krispies are suspended in molten marshmallows, more air is trapped in the interstices between the cereal. The cereal is a pretty nonconductive material, and the trapped air prevents heating due to convection. The light color of the cereal may also help by deflecting heat radiation. Of course, it probably helped that the Rice Krispies were about 1 ½ to 2 inches thick – compared to about a half inch of foam in the standard can cozy. But 2 inches is about the average thickness of a Rice Krispies Treat.
Given that it was 103 degrees F in the shade when we tested the Rice Krispies Treat can cozy, we expected it might just melt into a puddle of sticky goo halfway through the trial. But it surprised us by holding together for well over an hour. At the end of the experiment it was a bit stickier on the outside and bottom, but not really any worse for wear. We sampled a portion and found it still edible and delicious.
My question: could one make an effective parka from Rice Krispie treats?