Mammals and birds are endotherms, which means they generate their own body heat through relatively high metabolic rates. That high metabolism requires energy, which these animals garner from food. We typically think of endotherms as warm-blooded; however, some of them are not warm all of the time.
Most active birds and mammals maintain relatively high and stable body temperatures – often around 100 degrees. But they also lose heat to the surrounding environment, especially during the cold winter months. [Read more…] about Hibernation: How It Works