A grizzly bear eats a frozen fruits during a hot summer day at Rio de Janeiro's zoo January 13, 2015. According to a local climate institute, temperatures in Rio de Janeiro on Tuesday rose up to 34 degrees Celsius (93.2 degrees Fahrenheit). (Photo by Sergio Moraes/Reuters)

A grizzly bear eats a frozen fruits during a hot summer day at Rio de Janeiro's zoo January 13, 2015. (Photo by Sergio Moraes/Reuters)

A grizzly bear eats a frozen fruits during a hot summer day at Rio de Janeiro's zoo January 13, 2015. (Photo by Sergio Moraes/Reuters)

A spider monkey eats ice cream during a hot summer day at Rio de Janeiro's zoo January 13, 2015. (Photo by Sergio Moraes/Reuters)

A Siberian tiger eats a frozen meat during a hot summer day at Rio de Janeiro's zoo January 13, 2015. (Photo by Sergio Moraes/Reuters)

A Siberian tiger eats frozen meat during a hot summer day at Rio de Janeiro's zoo January 13, 2015. (Photo by Sergio Moraes/Reuters)

A Siberian tiger eats frozen meat during a hot summer day at Rio de Janeiro's zoo January 13, 2015. (Photo by Sergio Moraes/Reuters)

A zookeeper (not pictured) sprays water to cool down an Indian elephant during a hot summer day at Rio de Janeiro's zoo January 13, 2015. (Photo by Sergio Moraes/Reuters)

A spider monkey eats ice cream during a hot summer day at Rio de Janeiro's zoo January 13, 2015. (Photo by Sergio Moraes/Reuters)

An Indian elephant steps on a block of frozen fruits during a hot summer day at Rio de Janeiro's zoo January 13, 2015. (Photo by Sergio Moraes/Reuters)

A bear named Ze Colmeia eats frozen fruit at the city zoo in Rio Janeiro, Brazil, Tuesday, January 13, 2015. Animals were given frozen snacks made from tropical fruits, chunks of meat and frozen yogurt to help ease the intense summer heat. (Photo by Silvia Izquierdo/AP Photo)