Master of throat singing (or Khoomei) Aikhan Orzhak (L) and model Choigana Kertek, dressed in traditional costume, perform during sunset at the Aldyn Bulak area on the bank of the Yenisei River outside the village of Ust-Elegest in Tuva region, Southern Siberia, Russia, October 7, 2015. The region is inhabited by Tuvans, historically cattle-herding nomads, who nowadays practise two main confessions – Buddhism and Shamanism. (Photo by Ilya Naymushin/Reuters)

Men cover their heads from the sun while riding on a motorcycle during a hot day in Cairo, Egypt, August 17, 2015. A heatwave killed at least 61 people across Egypt from Sunday to Tuesday and caused nearly 600 people to be admitted to hospital, Egypt's health ministry said on state news agency MENA on Wednesday. (Photo by Amr Abdallah Dalsh/Reuters)

A child plays beside an idol of the Hindu god Ganesh, the deity of prosperity, the day after it was immersed in the Yamuna river for the Ganesh Chaturthi festival in Delhi, India September 6, 2017. (Photo by Cathal McNaughton/Reuters)

With the help of some fake teeth and multiple exposures, New York AP photographer Eddie Adams' daughter Susan is transformed into a little ghoul on Halloween night, October 31, 1966. (Photo by Eddie Adams/AP Photo)

Armed female members of the militant Palestinian group Islamic Jihad carry Kalashnikov assault rifles as they take part in a rally to protest against US President Donald Trump's decision to recognise Jerusalem as the capital of Israel, in Gaza City on December 11, 2017. (Photo by Mohammed Abed/AFP Photo)

North Korean soldiers march during a military parade marking the 105th birth anniversary of the country's founding father Kim Il Sung in Pyongyang, North Korea, April 15, 2017. (Photo by Damir Sagolj/Reuters)

A young visitor interacts with a baby hippopotamus swimming in its enclosure at the Berlin Zoo on January 1, 2018. Tourists and locals flocked to the zoo in the German capital on the unseasonably warm first day of the year. (Photo by Odd Andersen/AFP Photo)

The Clavie, a burning barrel packed with tar soaked sticks fixed on the top of a pole, is surrounded by people at the Doorie Hill on January 11, 2018 in Burghead, Scotland. People welcome in the New Year with the fire ceremony which has ancient roots dating back to the 1750s, when the Julian calendar was reformed in Britain. It is believed to bring good luck for the coming year. (Photo by Jeff J. Mitchell/Getty Images)