A heat-stressed koala waits as a resident pours water on its back on December 19, 2015 in Adelaide, Australia. Adelaide is experiencing an extreme heatwave, with temperatures reaching over 40 degrees for five consecutive days. (Photo by Morne de Klerk/Getty Images)

An airplane crosses a nearly full-moon on its way to Los Angeles International Airport near Whittier, Calif., Thursday, December 24, 2015. Not since 1977 has a full moon dawned in the skies on Christmas. (Photo by Nick Ut/AP Photo)

A man sleeps between tombstones in front of his single-room home on a hot night in the Cairo Necropolis, Egypt, October 13, 2015. In the sprawling Cairo Necropolis, known as the City of the Dead, life and death are side by side. Amid a housing crisis in Egypt, and with the population of greater Cairo estimated at about 20 million, people count themselves lucky to have a place to call home in the graveyards that date back hundreds of years. (Photo by Asmaa Waguih/Reuters)

Peruvian shamans holding a poster of Russia's President Vladimir Putin perform a ritual of predictions for the new year at Morro Solar hill in Chorrillos, Lima, Peru, December 29, 2015. The ritual is an end-of-the-year tradition and the shamans called for world peace and wished good luck for the upcoming elections in Peru and the U.S. (Photo by Mariana Bazo/Reuters)

Villagers take part in Kolyada holiday celebrations in the village of Martsiyanauka, east of the capital Minsk, January 21, 2015. Local residents took part in the celebrations to mark the end of a pagan winter holiday Kolyada, which over the centuries has merged with Orthodox Christmas celebrations. (Photo by Vasily Fedosenko/Reuters)

A participant shows off a belt buckle during the 20th annual Seattle Invitationals, an amateur Elvis impersonator competition, in Seattle, Washington January 23, 2015. The event drew hundreds of spectators for 20 contestants at the Crocodile, a venue in Seattle's Belltown neighborhood. (Photo by David Ryder/Reuters)

A pilot inflates his balloon before the 37th International Hot Air Balloon Week in Chateau-d'Oex, January 24, 2015. According to the organizers, over 80 balloons from 20 countries are participating in the ballooning event in the Swiss mountain resort. (Photo by Pierre Albouy/Reuters)

A worker settles mud in a mold to make bricks at a brick factory in Tixtla, on the outskirts of Chilpancingo, in the Guerrero state, January 26, 2015. The worker earns a salary of 15 Mexican pesos, or one dollar, for every 100 bricks made on a working day of at least 5 hours. (Photo by Jorge Dan Lopez/Reuters)