This keeps them from getting hypothermia. They also have a thick layer of fat that helps maintain their body temperature. This layer of fat stores food energy, too. All of these adaptationsallow them to live in Arctic regions. Some people don't mean to.
Some people have no idea what they are doing.
But that doesn't make them totally innocent. They are still responsible. I can't tell you why those people kill. I think if we learn more about the way polar bears live we might be able to protect them. They are making a come back, but it might not be enough.