Heat

Heat is a type of energy. It moves from hot things to cold things. The sun, fire, and stoves all give off heat. Heat makes things feel warm. It can also melt ice or boil water.

How Heat Moves

Heat can move in three ways. It can travel through solid things like a metal spoon in hot soup. It can move in liquids and gases by flowing around. It can also travel through empty space as rays, like the sun's heat reaching Earth. Heat always moves from hotter places to colder ones.

An old portrait of Galileo, a famous scientist from long ago.
An old portrait of Galileo, a famous scientist from long ago. (Domenico Tintoretto / Wikimedia Commons)

Measuring Heat

We use thermometers to measure how hot or cold something is. This is called temperature. In the United States, temperature is often measured in degrees Fahrenheit. Most other countries use degrees Celsius. Water freezes at 32 degrees Fahrenheit or 0 degrees Celsius.

Fun Facts

  • The center of the Earth is as hot as the surface of the sun.
  • Rubbing your hands together makes heat from friction.
  • A hot drink cools down because heat moves into the cooler air around it.

Did You Know?

The hottest temperature ever recorded on Earth was over 130 degrees Fahrenheit in Death Valley, California.