Kangaroo rats can survive the desert because they do not sweat and have very oily coats. They come out of their burrows and are active following sundown to forage for food. They consume seeds that are high in carbohydrates. Their kidneys are very efficient because they can excrete waste without losing much water.
Arctic foxes conserve their heat because of their round compact bodies and short muzzle, ears, and legs. Also, their multilayered fur insulates their bodies.