Cold-blooded

Cold-blooded organisms (called poikilotherms - "of varying temperature") maintain their body temperatures in ways different from mammal and bird. The term is now outdated in scientific contexts. Cold-blooded creatures were, initially, presumed to be incapable of maintaining their body temperatures at all. They were presumed to be "slaves" to their environments. Whatever the environmental temperature was, so too was their body temperature. Cold-blooded animals are now called ectotherms, a term which signifies that their heat (therm) comes from outside (ecto) of them; the term cold-blooded is misleading. Advances in the study of how creatures maintain their internal temperatures (termed: Thermophysiology) have shown that many of the earlier notions of what the terms "warm-blooded" and "cold-blooded" mean, were far from accurate (see below: Definitions). Today scientists realize that body temperature types are not a simple matter of black and white. Most creatures fit more in line with... full article at wikipedia