Penguins have a unique feather arrangement and body structure that provides excellent insulation. Their feathers are short and densely packed, which not only minimizes friction and turbulence in water to help penguins swim but also traps a layer of air close to the skin. This air layer acts as an insulator, keeping the birds warm even in freezing temperatures. Additionally, penguins’ bodies are covered with a thick layer of fat that further insulates them against the cold.

Because the skin on penguins’ feet is bare and frequently in direct contact with ice, penguins have a specialized system of thermal conduction in their bodies that helps them conserve heat. This system involves closely aligned arteries and veins in their lower limbs, which allows for the transfer of heat from warm blood flowing out from the center of the body to the cooler blood returning from the extremities. This countercurrent heat-exchange system ensures that a penguin’s body temperature remains stable, even when its feet are in contact with ice or cold water.

Behaviorally, penguins employ several strategies to maintain warmth. One of the most notable to humans is their tendency to gather in large groups, especially during harsh Antarctic storms. By forming tightly packed crowds, or huddles, penguins share body heat and protect themselves from the wind and cold. This communal behavior is also crucial for the survival of their young, which are sheltered under the bodies of their parents in their early days and, as they grow older, stay close to their parents’ side to minimize exposure to the elements.