 Heat transfers through our environment all of the time. I'm sure you've noticed that walking on a beach in summer feels hot. Diving into the pool feels cold. And eating an ice cream cone on a hot summer's day goes from cold to cool to warm to melt it all over your hand at a rapid rate. Heat transfer happens to us all the time, every day. It always moves from hot objects to colder ones and is impacted by some materials more than others. In this lesson you'll explore three ways heat transfers in our environment, conduction, convection and radiation. Conduction is the transfer of heat between substances directly contacting each other. The better the conductor, the more rapidly heat will transfer. Wood conductors include copper, silver, iron and steel. Poor conductors include wood, styrofoam, paper and air. It's why we don't recommend picking up a handful of change that's been sitting in the sun unless you want to burn your hands. But you're okay to pick up that pile of wooden nickels sitting next to it. Moving on to convection. This is the up and down movement of gases and liquids caused by heat transfer. As a gas or liquid is heated, it warms, expands and rises because it's less dense. When the gas or liquid cools, it becomes denser and falls. Warming and rising and cooling and falling creates a convection current. This is the primary way heat moves through gases and liquids. Some examples include the warmer water on a pool surface, floating in a hot air balloon and that cool evening breeze blowing through the lower floors of your house or apartment. Finally, let's talk about radiation. This is defined as electromagnetic waves traveling through space. When electromagnetic waves come in contact with an object, the waves transfer the heat to that object. It's heat traveling in the form of visible and non-visible light. Some examples of radiation include feeling warm while standing next to a campfire, reheating that slice of pizza in your microwave and turning on a light so you can find your phone. Conduction, convection and radiation are three critical ways heat moves through our lives. They're the heat transfer principles we experience every day. Knowing how heat transfers makes it easier to find efficient ways to warm and cool our houses, keep people safe from overheating and create new and innovative technologies to improve our lives. This completes this lesson on heat transfer. Conduction, radiation, convection.