In what way is a polar bear suited to its environment?

their fur is white is a a great camouflage against man trying to hunt them, they have several layers of fur and fat to protect them against the cold, they have small ears so there ears can keep warm and there blood can't take the heat away.
They are so well insulated that they give off no detectable heat when out on the ice, and are invisible to infrared (heat-sensing) Photography except for a small spot just in front of their nose, made by exhaled breath. On cold days they may dig a hole, curl up and even cover their nose with a paw. On warm days, they pant, may sleep anywhere in almost any position, and may be sprawled out with unfurred foot pads waving in the air.

Contrary to popular belief, the polar bear's fur neither acts like a fiber optic nor "solar heating" system. All visible light is reflected (which is why we see the bear as white), and UV light (which is present in the Polar Region only for the warmest, 4 months of full summer light) is only superficially absorbed at the ends of the guard hairs. The skin is also black, enabling the bear to absorb UV rays and thus keep warm. However, a polar bear's primary insulation is by the thick fat pad. They also have slightly webbed feet that make them great swimmers. They have an extra eyelid that is transparent, it lets them see while under water and at the same time protects the cornea of the eye. They long snout helps warm the inhaled air before it gets to the lungs.