Paul, 9, dumps a bucket of water over his head at a fountain near government buildings during hot weather on July 1, 2015 in Berlin, Germany. Temperatures across northern Europe are rising and in Germany a high of 36 degrees is forecast for the weekend. (Photo by Sean Gallup/Getty Images)

A humanoid robot works side by side with employees in the assembly line at a factory of Glory Ltd., a manufacturer of automatic change dispensers, in Kazo, north of Tokyo, Japan, July 1, 2015. Japanese firms are ramping up spending on robotics and automation, responding at last to premier Shinzo Abe's efforts to stimulate the economy and end two decades of stagnation and deflation. (Photo by Issei Kato/Reuters)

A farmer works in a paddy field at Reba Maheswar village, 56 kilometers (35 miles) east of Gauhati, India, Friday, July 3, 2015. Rice is one of the most important food crops of India and about 4,000 different varieties are grown in different parts of the country. (Photo by Anupam Nath/AP Photo)

A man paddles a makeshift boat along a flooded street in Guasdualito, in the state of Apure, Venezuela, July 4, 2015. A total of 9,000 families have been affected by the overflowing of rivers Arauca and Sarare in Guasdualito, Apure state, because of the heavy rains in recent days in this area of the country, local media reported. (Photo by Carlos Eduardo Ramirez/Reuters)

A man poses for a photo with a life size cutout of Pope Francis at Bicentennial Park where the pontiff celebrated Mass for an estimated half-million people, in Quito, Ecuador, Tuesday, July 7, 2015. Francis told an estimated half-million people gathered for the Mass that in a world divide by wars, violence and individualism, Catholics should be “builders of unity”, bringing together hopes and ideals of their people. (Photo by Ana Buitron/AP Photo)

NFL player Rob Gronkowski, of the New England Patriots, from second left, accepts the best comeback athlete award with his brothers, NFL free agent Chris Gronkowski and former NFL player Dan Gronkowski at the ESPY Awards at the Microsoft Theater on Wednesday, July 15, 2015, in Los Angeles. (Photo by Chris Pizzello/Invision/AP Photo)

A participant of the Castle Party festival poses for picture as a man walks past in Bolkow, southwestern Poland, July 16, 2015. The annual festival features around 50 musicians and artists playing on various stage Gothic rock and other styles of the dark music subculture. Outside Germany, it is one of the biggest festival with this genre of music, the event attracts regular international audience of up to 5000, the organizers said. (Photo by Kacper Pempel/Reuters)

A man wearing a Guy Fawkes mask enjoys a ride on a 350-meter (1148 feet) long water slide during 2015 City Silde Festa in central Seoul, South Korea, July 19, 2015. A 350 meter-long waterslide has been installed in downtown of Seoul, the longest waterslide to be recorded in Korea, according to local media. (Photo by Kim Hong-Ji/Reuters)