also cold blooded; 1590s, of persons, "without emotion, unfeeling;" of actions, from 1828. The phrase refers to the old notion that blood temperature rose with excitement. In the literal sen [..]

having a body temperature that adjusts to the surrounding environment.

having a body temperature that is regulated by the environment

cf. Ectothermic - animals that cannot regulate their body temperature relative to the environment.

An animal's ability to change its body temperature with its surrounding environment.

having a body temperature that can change somewhat with changes in the temperature of the environment. cold front -

(adj) without compunction or human feeling(adj) having cold blood (in animals whose body temperature is not internally regulated)

An animal whose body temperature changes with the temperature of the air or water around it, as a turtle or fish.

Animals that do not maintain a constant internal body temperature; instead, their temperature is greatly influenced by their environment.

An outdated term referring to living organisms with body temperatures that adapt to the

An animal that cannot maintain its own body heat therefore having to absorb heat from its environment.