Insulation to stay warm
Imagine yourself, being one of those hardy souls that accepts the challenge of a “polar bear plunge” festivity, by throwing their warm body into frigid ocean water. That is a challenge to any warm, mammalian body and just as all mammals, marine mammals need to maintain a body temperature of 98.6℉ (37℃). To be able to do that, they have evolved several anatomical and behavioral adaptations to neither overheat nor get too cold. For example, they use blubber and/or fur as insu