This experiment was performed by Dee Hellmers' 2nd grade class at Hall Kent Elementary School in Homewood, Ala.
- 2 small plastic zip bags filled with ice
- 2 larger plastic zip bags
Seal the two smaller bags filled with ice. Place each inside one of the larger bags. Squeeze the air out of one of the larger bags and seal it. Seal the second bag except for one corner. Blow air into this bag until it is inflated like a pillow. Carefully seal it. Place one hand on the "pillow" bag and your other hand on the sealed bag.
The bag filled with a layer of air does not feel as cold as the bag without the layer of air. The layer of air helps trap your body heat and insulates your hand from the cold.
Did you know?
A layer of trapped air under tightly packed feathers helps penguins stay warm. Dr. McClintock and others divers in the cold Antarctic water wear a dry suit under their wet dive suit. They pump in a layer of air between the two suits to help them stay warm.