How does blubber help seals survive in cold water?

Blubber is a thick layer of fat and collagen that serves as a vital insulating adaptation for many marine mammals, including seals, to survive in cold water.1

Because water has a much higher thermal conductivity than air, mammals lose body heat significantly faster when submerged. Blubber helps seals survive these conditions by acting as a poor conductor of heat, effectively trapping the animal's internal warmth and preventing it from escaping into the frigid environment. In addition to providing insulation, this layer allows for a specialized network of blood vessels that helps the animal regulate its body temperature. By reducing heat loss, blubber enables seals to maintain homeostasis while living in environments that would otherwise cause rapid cooling.12