Soldiers of China's People's Liberation Army (PLA) jump as part of their winter training in temperature of negative 26 degrees Celsius at China's border with Russia in Heihe, Heilongjiang province, December 14, 2015. (Photo by Reuters/Stringer)

In a handout picture released by the British Ministry of Defence via their Defence News Imagery website on August 22, 2016, Nils Olav the penguin inspects the Guard of Honour formed by His Majesty the King of Norway's Guard on August 22, 2016 at Edinburgh Zoo in Scotland. His Majesty the King of Norway's Guard paid a very special visit to RZSS Edinburgh Zoo to bestow a unique honour upon resident king penguin Sir Nils Olav. Already a knight, the most famous king penguin in the world was given the new title of “Brigadier Sir Nils Olav”. (Photo by Mark Owens/AFP Photo)

A dancer performs during Portuguese designer Teresa Martins for TM Collection during her runway show at the 41st edition of the Portugal Fashion Event in Lisbon, Portugal, 14 October 2017. (Photo by Jose Sena Goulao/EPA/EFE)

Girls rest on stairs at the China Digital Entertainment Expo and Conference (ChinaJoy) in Shanghai, China July 27, 2017. (Photo by Aly Song/Reuters)

A spectator cools herself at a water spraying fan at the Australian Open tennis championships in Melbourne, Australia, Tuesday, January 17, 2017. (Photo by Kin Cheung/AP Photo)

A boat is stranded on Poyang Lake in Lushan City, China during low-water season on November 3, 2016. (Photo by Xinhua/Barcroft Images)

In this photo provided by Skydive Chicago, escape artist Anthony Martin falls while handcuffed and locked inside a box after being dropped from an airplane over Ottawa, Ill., Tuesday, August 6, 2013. (Photo by Joe Silva/AP Photo/Courtesy of Skydive Chicago)

Ryan Randall plays the bagpipes outside a polling station in Edinburgh, Scotland September 18, 2014. Polling in the referendum on Scottish independence began on Thursday morning, as Scotland votes whether or not to end the 307-year-old union with the rest of the United Kingdom. (Photo by Paul Hackett/Reuters)