How do sea otters keep warm?
They have the world’s densest fur—up to a million hairs per square inch! (You have 100,000 hairs or less on your whole head). A sea otter’s normal body temperature is about 100° F (38° C), while the ocean is a chilly 35° to 60° F (2-16° C). Sea otters carefully groom their fur to trap a layer of insulating air bubbles between their warm skin and the icy water. But even that fur can’t stop the loss of body heat. Otters need to keep that fur in good condition to stay alive in the cold water. That’s why oil spills and even oil runoff from streets is bad for the otters—oil degrades the otters’ fur and they get cold.
