Dolphins have a layer of blubber, or fat, under their skin. This layer of blubber helps to insulate the dolphin's body and keep the heat inside. The blubber is also a source of energy that the dolphin can use when food is scarce.
Active metabolism
Dolphins have an active metabolism, which means that they produce a lot of body heat. This is because dolphins swim constantly, and their muscles generate heat. The heat produced by the dolphin's metabolism is also helped to keep the dolphin warm.
Large size
Dolphins are large animals, and their size also helps to keep them warm. The larger an animal is, the more heat it can produce and retain.
Heat exchange
Dolphins also use heat exchange to help them stay warm. When a dolphin swims, the warm water from the environment passes over its body and the dolphin absorbs the heat. The dolphin then releases the heat back into the environment when it swims into colder water.
Behavioral adaptations
Dolphins also use behavioral adaptations to help them stay warm. For example, dolphins may huddle together in groups to conserve body heat. They may also swim in shallow waters, where the water is warmer.