Well for starters, that means that the air in the sky is very cold, and has a lower temperature. Since it is super dark, it is colder than the polar bear.
The polar bear is cold. Not as cold as the sky, and not as warm as the mouth and eyes, but it is still very cold. This is probably because it lives in a snowy and cold climate.
The polar bears eyes and mouth are warm. This is because, the spots where the eyes, mouth, and nose are is a very light shade. This concludes that those spots on the polar bear are warm.
