A polar bear has a bucket on his head while a cub polar bear swims nearby in the cooling waters of Moscow Zoo, on Wednesday, July 21, 2010. A heat wave hit central Russia breaking temperature records going higher than 30°C (86°F) for the last two weeks. (AP Photo/Misha Japaridze)

A polar bear has a bucket on his head while a cub polar bear swims nearby in the cooling waters of Moscow Zoo, on Wednesday, July 21, 2010. A heat wave hit central Russia breaking temperature records going higher than 30°C (86°F) for the last two weeks. (AP Photo/Misha Japaridze)