Bill Nye explains that heat is energy and can be used to do work, such as keep up warm, run an engine, or affect other molecules. Using real-world examples, he then describes the three ways that heat can move from one place to another: conduction, convection, and radiation.
Hank explains why solid water is less dense than liquid water even though solids are typically more dense than liquids. He also discusses how the high heat capacity of water helps support life on Earth. He uses the bodily process of sweating to exemplify water's unique properties.
Dr. C and Phil explain how the window could be freezing cold to the touch, even though the rest of their cabin is very warm. She explains the difference between conductors and insulators of heat through materials.