Endothermic vs. Ectothermic

Endothermic and Ectothermic. While we might normally refer to these as ‘warm-blooded’ and ‘cold-blooded’, this isn’t entirely accurate, and the term “cold blooded” has a negative association with being mean and cruel.


  • Is when an animal has a set body temperature that it’s able to maintain regardless of the outside environment
  • In order to help maintain their body temperature in warm weather, many endothermic animals do different things to cool down, such as panting and sweating
  • In order to help maintain their body temperature in cold weather, endothermic animals can have a layer of insulation to keep their heat in, such as fur, feathers, or even a thick layer of fat called blubber!

Endothermic animals include



  • Is when an animal does not have a set body temperature and takes on the temperature of their surroundings
  • Ectothermic animals need to rely on outside sources to control their body temperature
  • Ectothermic animals can use the sunlight as a head source to warm up (this is called basking)
  • To cool down, ectothermic animals can go into the shade or underground
  • ectothermic animals tend to be more active in warm weather, and more sluggish in cold weather

Many groups of animals are cold blooded

  • Reptiles (such as snakes, lizards and tortoises)
  • Amphibians (such as frogs and salamanders)
  • Even some mammals have been known to be unable to regular their body temperature, such as echidnas and naked mole rats!

Keep Exploring Defenders!