How do otters stay warm in cold water?

Otters stay warm in cold water thanks to their dense fur, which is the thickest of any mammal. Their fur traps a layer of air close to their skin, providing insulation and preventing heat loss. Sea otters also have a high metabolic rate, which generates body heat to sustain them in chilly environments. They frequently groom their fur to maintain its insulating properties, ensuring they stay warm while hunting and swimming.