Hibernation and  Aestivation

Hibernation, aestivation and daily torpor are states in which the animal relaxes its homeothermic processes almost completely within a certain range of ambient temperatures and, like a Poikilotherms, allows its body temperature to equal ambient temperature. When body temperature is fixed to approximate ambient temperature for periods of several days or longer during winter, the phenomenon is termed hibernation. When this occurs during summer, it is called aestivation.