Think you have cold winter where you live? Not when you compare it to the animals that live at the Arctic Circle. The animals live in a harsh, frozen landscape that can be dark for long periods of time. Some of the animals have adapted to their environment in some very unusual ways. For instance, the frogs that live there freeze three-quarters of their body. This causes its heart to stop beating. It will hibernate like this until spring. Read "Survival at 40 Below" to learn more about the extraordinary lengths the Arctic animals go to survive.