View of an egg fried on the pavement in Pozo Hondo, Santiago del Estero, Argentina on January 23, 2016, while the real feel was 57 degrees Celsius. Pozo Hondo's Mayor Claudio Nicolau fried an egg on the pavement of the main square of the city Saturday. (Photo by AFP Photo/Stringer)

People look at a man, who residents said was killed by al Qaeda militants, hanging on a bridge in Yemen's southeastern city of Mukalla June 17, 2015. Al Qaeda militants in Yemen killed two alleged Saudi spies, residents said, accusing them of planting tracking devices which enabled the assassination of the group's leader in a suspected U.S. drone strike. (Photo by Reuters/Stringer)

A Pakistani vendor tries to salvage materials after flood water destroyed his shop following heavy rain on the outskirts of Peshawar on April 4, 2016. (Photo by A. Majeed/AFP Photo)

Justin Nelzen, in red vest, joins others as they work to rescue up to 70 horses along Cypresswood Drive near Humble along Cypress Creek, Monday, April 18, 2016, in Houston. More than a foot of rain fell Monday in parts of Houston, submerging scores of subdivisions and several major interstate highways, forcing the closure of schools and knocking out power to thousands of residents who were urged to shelter in place. (Photo by Mark Mulligan/Houston Chronicle via AP Photo)

African women in their grandmothers' clothes: Joana Choumali’s portraits show modern African women swapping jeans for kente cloth – and diving into the dazzling cultural heritage of their families. (Photo by Joana Choumali/The Guardian)

A four-day old African spurred tortoise, Geochelone sulcata, one of eight babies, was place on the head of its mother in their enclosure in Nyiregyhaza Animal Park in Nyiregyhaza, 226 km east of Budapest, Hungary, 27 September 2011. This was the first time that offspring of an African spurred tortoise were born in this zoo. The eight babies hatched after 115 days, they are 5.5 cms long and weigh 25 grams. Spurred tortoise is the largest species of land tortoises in Africa, the weight of an adult animal may reach 80 kgs. (Photo by Attila Balazs/EPA)

A riot policeman watches as a police vehicle burns in Braamfontein, Johannesburg, South Africa, Tuesday, October 25, 2016. Rioters in South Africa set a police vehicle on fire Tuesday and stoned vehicles near a Johannesburg university that has been the scene of sometimes violent protests by students demanding free education. The violence broke out in streets near the University of the Witwatersrand at around the same time that student protesters met and marched off the campus, South African media reported. (Photo by Yeshiel Panchia/AP Photo)

In this June 20, 2015 photo, Niberta Galvez uses the bottom half of his shirt to collect coca leaves in Samugari, Peru. Coca farmers were among the locals who, in 1984, formed citizen militias to help the military beat back Shining Path rebels, reducing them to a small group of fewer than 500 who now are deeply involved in drug trafficking. (Photo by Rodrigo Abd/AP Photo)