A peformance artist attends an election rally for Cameroon presidential candidate for the opposition Univers party, Cabral Libii in Yaounde, Cameroon 06 October 2018. Africa's oldest president Paul Biya who has been in power since 1982 is up against eight candidates when voters go to the polls 07 October 2018. 6.9 million registered voters will head to the polls but marginalised anglophone separatists in the North West and South West of the country threaten to disrupt the elections. (Photo by Nic Bothma/EPA/EFE)

Fishermen catch fish at Mao'er lake at the start of winter fishing season which is a local custom to welcome the new year on December 29, 2018 in Huaian, Jiangsu Province of China. (Photo by VCG/VCG via Getty Images)

Icicles are seen on a handrail along the coast at Donggang business district in Dalian, Liaoning province, China on December 27, 2018. (Photo by Reuters/China Stringer Network)

An elderly man uses a fan to shade himself from the sun as he walks in a public park in Beijing, Tuesday, June 7, 2016. Thursday marks the Duanwu Festival, a public holiday in China celebrated with outdoor activities including dragon boat races. (Photo by Mark Schiefelbein/AP Photo)

Firefighters of the Texas Canyon Hotshot crew fight the Sand Fire on July 23 2016 near Santa Clarita, California. Fueled by temperatures reaching about 108 degrees fahrenheit, the wildfire began yesterday has grown to 11,000 acres. (Photo by David McNew/AFP Photo)

Winter swimmers dressed in ballet costumes pose for a photo before diving into the icy water, during a snowfall at a park in Shenyang, Liaoning province, China on February 15, 2019. (Photo by Reuters/China Stringer Network)

A woman stands on the footbridge over the river Garry near Pitlochry, Scotland, Britain on October 10, 2018. (Photo by Russell Cheyne/Reuters)

In this undated handout photo taken by mrwed54, a woman poses for a photo by a lake in the Siberian city of Novosibirsk, about 2,800 kilometers (1,750 miles) east of Moscow, Russia. Thousands of Novosibirsk residents, from scantily clad women to newlyweds have been instagramming selfies near the lake nicknamed the “Siberian Malvides” after the far-flung tropical islands in the Indian Ocean. This is in fact is a man-made dumb of coal from a nearby power station that provides for most of Novosibirsk’s energy needs. Environmentalists are warning people against coming into contact with the water. (Photo by mrwed54 via AP Photo)