See the Difference
Look at the image of a hand holding a lizard. This image was taken with a special camera. It shows how much heat an object gives off.
hand
lizard
HOTTER
COLDER
This elephant cools down by fanning its ears.
This spider’s body is cooler than its environment.
The hand is warm. It shows up in red. The lizard is colder. It shows up as blue. Before being held, it was dark blue, like the background. What happens when the lizard and the person touch?
The lizard gets heat from the person’s hand. Its body warms up. Now, its feet and legs show up as green and yellow.
HOTTER
COLDER
This cat makes its own body heat. It leaves behind a trail of warm pawprints.
Watch as a person leaves warm footprints on a cold floor.
COLDER
HOTTER
gharial
The sun helps warm this reptile.
Birds are a good example. They need a lot of energy to fly. Food gives them that energy. As their bodies use up the food, they have the energy to fly and to stay warm at all times.
Food and Energy
Some animals can keep a steady body temperature. Others cannot. Why? It has to do with energy and food.
Food gives animals energy. Energy helps make heat. Endotherms need to eat a lot to have enough energy to stay warm.
HOTTER
COLDER
meerkats
These meerkats control their own body heat.
flamingos
HOTTER
COLDER
Some of these flamingos have one leg that is hotter than the other. When a flamingo stands on one leg, that leg loses heat, while the other leg is tucked up next to its body keeping warm.
