Cold Blooded and Warm Blooded Animals

What is the difference between animals that are warm blooded and those that are cold blooded?

Basically, this has to do with how animals keep their body the right temperature they need to be in order to survive.  The outside temperature can be much colder or warmer than the animals’ body, so how do animals keep their body the correct temperature all of the time?

For humans, whenever you check your temperature with a thermometer you can check if you have a fever and are sick or if you are normal.  Normal temperature for humans is 98.6 degrees F.  If you temperature goes up to 99 or 100 degrees F you definitely notice it and don’t feel well.  If your temperature goes up as high as 104 degrees F you feel absolutely awful.

warm blooded human

Humans can live in areas that get cold because they keep their body temperature about 98.6 degrees F all of the time.

Humans bodies are able to keep our temperature about 98.6 degrees F in the middle of winter when it is 10 degrees F outside or during the summer when it is 110 degrees F outside.  Our bodies are able to maintain or regulate our own temperature.  This means that humans are warm blooded.

What does it mean to be warm blooded?

Animals that are warm blooded are able to regulate their own body temperatures.  This means that those animals do not need to do anything special if it gets warm or cold outside in order to keep their body at their normal temperature.  Warm blooded animals change the food they eat into energy, some of which they use to keep their bodies the correct temperature.

warm blooded mammal

Raccoons are warm blooded and can live in the snow.

If warm blooded animals are too cold then they use some energy to warm themselves up, and if they are too hot they cool themselves off by doing something like sweating or panting.  All of this warming up and cooling off of their bodies means that these animals need to eat more food than cold blooded animals because it takes a lot of energy to keep a constant body temperature.

One good thing about being a warm blooded animal is that these animals can be active anytime no matter what the temperature is outside as long as they have enough energy.  This allows them to live just about anywhere in the world.

Endotherm – the scientific name for warm blooded animals, meaning animals that can regulate their own body temperature.

Warm Blooded Animals:

Mammals

Birds

What does it mean to be cold blooded?

Cold blooded animals can not maintain their own body temperature, instead they become the temperature of their surroundings.  If it is cold outside, their bodies become cold and if it is hot outside they become hot.

Since cold blooded animals body temperature is changing their activity levels also change a lot.  When they are cold they become less active and sluggish, but when it is warm out they are more active.  This is because their muscles work faster when their body is warmer.  Cold blooded animals do not live in high mountains (such as high up in the Rocky Mountains) because it is just too cold there and they can not survive since their bodies are too cold and inactive to get food.

cold blooded snake

Snakes are cold blooded and need to lay out in the sun to warm up and become active.

One good thing about being cold blooded is that these animals do not need to eat as much food as warm blooded animals.  This is because they do not need to use lots of energy just to maintain their body temperature like warm blooded animals do.

Ectotherm – the scientific name for animals that can not maintain their own body temperature.

Cold Blooded Animals:

Reptiles

Fish

Amphibians

Insects