Four-year-old Solaris Arias (right) jumps through water spraying from an open fire hydrant in Providence, Rhode Island, on June 20, 2012. Much of the state remained under a heat advisory Tuesday afternoon because of the steamy air mass that has moved into the region resulting in temperatures in the 90s. (Photo by Steven Senne/AP Photo)

A biker passes by a pair of mailboxes in the Capitol Hill neighborhood November 6, 2012 in Denver, Colorado. Colorado is considered by most experts to be one of the key battleground state in this year's presidential election. (Photo by Marc Piscotty/AFP Photo)

A member of staff stands in front of a CRH high-speed train at Shanghai Hongqiao Railway Station during its test run on May 11, 2011 in Shanghai, China. After 3 years construction, from April in 2008, with total investment estimated at 220.9 billion yuan (around 32.5 billion U.S. dollars), the Beijing-Shanghai high-speed railway begins a one-month trial operation. It is expected to start operation in June this year, with the travel time between the two cities reducing to five hours from the previous 10. (Photo by ChinaFotoPress/Getty Images)

A polar bear cub snuggles up against her mother Valeska, in their enclosure at Bremerhaven's (Bremen's) Zoo by the Sea, Germany March 9, 2016. The female cub, who is yet to ne named, was born on December 11 last year. (Photo by Carmen Jaspersen/Reuters)

Enjoying a tickle from her keeper, an orphaned orangutan at the SOCP Quarantine Centre in Sumatra, Indonesia on March 20, 2016. The island’s orangutan population has been devastated in recent years as the forest areas are destroyed to make way for palm oil plantations. (Photo by Jami Tarris/Barcroft Media)

A boy collects drinking water from a hand pump in Kutubdia, Bangladesh on March 30, 2016. Kutubdia is one of many islands affected by some of the fastest recorded sea-level rises in the world. The island has halved in size in 20 years. (Photo by SIipa/Rex Features/Shutterstock)

Female sea lion “Sarasa” holds a hose with her mouse to help a trainer clean her room at the Shinagawa Aqua Stadium aquarium in Tokyo on December 30, 2014. The aquarium is carrying out year-end general cleaning of their facilities. (Photo by Yoshikazu Tsuno/AFP Photo)