Heterothermic (from Greek: hetero = "other" thermy = "heat.") is a physiological term referring to a unique case of poikilothermy. Heterothermic creatures are homeothermic for a portion of the day, or year. More often than not, it's usually used as a way to dissociate the fluctuating metabolic rates seen in some small mammals & birds (for example bats & hummingbirds), from those of traditional cold blooded animals. In many bat species, body temperature and metabolic rate, are elevated only durin… (More on Heterothermic)