Chicago Zoological Society press release:
Today, with temperatures heating up, animals at Brookfield Zoo received some ice treats. Animal care staff provided several of the zoo's animals, including polar bears, grizzly bears, Amur tiger, sloth bears, and even the rhino with ice. Some of the frozen treats were filled with fruits and vegetables while others had bones and meat depending on the species. The polar and grizzly bears also received 300-pound blocks of ice, but seemed to prefer the smaller ones with the frozen treats inside. Also, some of the outdoor habitats like the reindeers’ have water misters so the animals can cool off. In addition, animals such as the bears and big cats are given access to their indoor quarters if they choose.