What are cold blooded animals?

Animals classified as cold-blooded are those whose blood temperature fluctuates with the outside temperature of the atmosphere. These animals are unable to endure extremely cold temperatures during severe winters because their blood temperature will also drop and may even freeze if the atmosphere reaches zero degrees Celsius. All reptiles, including snakes, lizards, and other creatures, are cold-blooded and hibernate, emerging from deeper soil layers in the springtime.

The blood temperature of warm-blooded animals—all mammals, for example—remains constant regardless of variations in the outside temperature.

Cold-blooded animals, also known as ectothermic animals, are organisms that rely on external sources to regulate their body temperature. They cannot regulate their internal temperature internally. Examples include reptiles, amphibians, fish, and most invertebrates.