This picture taken on February 23, 2014 shows participants wearing dresses running half-naked in the annual 3.5 km Undie Run held in the Olympic Forest Park smog-covered Beijing. Some 200 participants took part in this event, many of them with gas masks, as dangerous smog blighted swathes of northern China in recent days. (Photo by AFP Photo/STR)

An Egyptian carries bread tray over his bicycle, in Cairo, Egypt, Saturday, November 19, 2016. Egypt is currently suffering an acute foreign currency shortage because of the decimation of its lucrative tourism industry, double digit rates of inflation and unemployment. (Photo by Amr Nabil/AP Photo)

The adventurous explorers have snapped themselves in shark-infested waters, at the side of an active volcano, atop a Hong Kong skyscraper surrounded by toxic smog, and even perched on the top of iconic Rio statue of Christ the Redeemer. Here: Ervin Punkar using a selfie stick to take a photo from the very top of the 600ft TV tower in Tartu, Estonia. (Photo by Ervin Punkar/Caters News Agency)

People immerse themselves in an ice hole in the Chulym river, with the air temperature at about minus 12 degrees Celsius (10.4 degrees Fahrenheit), during celebrations for the Russian Orthodox Epiphany outside of the town of Nazarovo, Krasnoyarsk region January 19, 2015. (Photo by Ilya Naymushin/Reuters)

A group of stags charge across a frosty field in Bushy Park, London, leaping in near-perfect formation as the early morning mist hangs low in the second decade of December 2025. (Photo by Max Ellis/The Times)

The remarkable scene was captured by amateur wildlife photographer Ian Salisbury, 62, at the South Luangwa National park in Zambia. The crocodile grabs hold of the elephant's trunk, but it soon becomes clear that he has bitten off a lot more than he can chew by grabbing the huge beast. Mr Salisbury said the elephant “fled rapidly into the bush” after the attack. (Photo by Ian Salisbury/Caters News)

Brush your teeth and get cleaned up for the week ahead! These animals answered the call of good dental hygiene. Here: Hamster holds toothbrush. (Photo by Neo Vision/Getty Images/Amana Images RM)

Picture dated October 2nd, 2022 shows the Northern Lights over Northumberland, United Kingdom. (Photo by Dan Monk/Bav Media)