Polar bears roam the Arctic ice where winter temperatures average
-29°F (-34°C). These mammals have an internal temperature very close to our own, 98.6°F (37°C); however, they
are not bothered by the cold. Instead, they are protected with multiple layers of insulation which may suggest improvements
for the design of buildings and apparel.
A layer of blubber 4-5 inches thick lies beneath the adult skin which
is black in color. This skin, in turn, is covered with dense fur. The fur actually is colorless, and scatters sunlight to
give the familiar white color. The individual hairs are hollow, trapping air for insulation. This feature has been copied
by hollow textile fibers in light-weight winter jackets and sleeping bags. The bear's hair strands also may provide a fiber
optic pathway to deliver sunlight to the skin. The dark skin itself is an excellent absorber of light energy.
Polar bears are virtually undetectable when photographed with infrared
film. This means that they simply do not lose measureable body heat. For military application, polar bear design suggests
camouflage clothing which avoids infrared detection.
J.A. and many others. 2002. Radiative properties of polar bear hair Proceedings of the ASME International Mechanical Engineering
Congress and Exposition. BED-53:1-2.