Figure 39.14 Adaptations to Cold and Hot Climates (A) The antelope jackrabbit is found in the Sonoran Desert of Arizona. Its large ears serve as heat exchangers, passing heat from the animal’s blood to the surrounding air. (B) The thick fur of the Arctic hare provides insulation, and its rounded body shape lowers its surface area-to-volume ratio. The ears and extremities are smaller than those of its warm-climate relatives, so less heat is lost to the environment.