What keeps whales and walruses warm in bone-chilling water? One thing is the thick layer of fat under their skin, called blubber. Blubber acts as insulation between the animal's inner organs and the chilly ocean.   Marine mammals that live in extremely cold environments usually have a thicker layer of blubber than those that swim in warmer places. An animal's behavior can also affect the thickness of its blubber. Whales that swim slowly tend to have a thicker layer of blubber than faster-swimming whales. Why do you think this is? (HINT: Think of how you feel when you're running in cold weather compared to when you're standing still in it.) Overview: In this experiment, you'll create two gloves — one that contains a layer of shortening (blubber) inside, and one that doesn't. By putting both glove-covered hands in a bucket of freezing c-c-c-cold water, you'll find out if the blubber-covered hand feels warmer than the hand without the fat layer.