A couple covered in mud wait for it to dry at the Salt-works lakes near the Black Sea town of Burgas in Bulgaria on July 25, 2019. Thousands of tourists visit the red salt lakes for mud baths, which are believed to help the healing of muscular disorders and rheumatism. (Photo by Nikolay Doychinov/AFP Photo)

A design studio has launched its own dogs of war – by cleverly blending iconic Second World War planes with their canine counterparts. Photo: Wellington bomber with Golden Retreiver camoflage. A design studio has launched its own dogs of war – by cleverly blending iconic Second World War planes with their canine counterparts. (Photo by BNPS)

Models painted in camouflage colours to blend in with the background pose for Chinese artist Liu Bolin's artwork “Dongji”, or Winter Solstice, on the second day after China's capital Beijing issued its second ever “red alert” for air pollution, in Beijing, China, December 20, 2015. In this artwork, Liu wants to express his concerns about China and its people, including air pollution problem, Liu told Reuters. (Photo by Kim Kyung-Hoon/Reuters)

A military cadet gets help from a colleague to adjust her hair before taking part the military parade in Bucharest, Romania, Saturday, December 1, 2018, as thousands turned out Saturday to celebrate 100-years since Romania became a modern-day state, amid concerns about rule of law and the state of democracy. Crowds braved temperatures of minus 5 Celsius (23 Fahrenheit) to watch the military parade of troops, tanks and military vehicles. (Photo by Vadim Ghirda/AP Photo)

A three-year-old girl smokes a cigar during the Saint Simon celebrations in San Andres Itzapa, Guatemala, on October 28, 2019. Thousands believe that the saint helps people find work, solves family problems and cures illnesses. (Photo by Orlando Estrada/AFP Photo)

Bathers brave the cold waters of the North Sea as they take part in the annual Boxing Day dip at Redcar Beach on December 26, 2019 in Redcar, England. The event attracts hundreds of people each year who take to the cold water wearing fancy dress as they help to raise money for a number of charities. (Photo by James Glossop/The Times)

A soldier helps another with her ear protection at the Terningmoen Camp in Elverum, Norway on March 23, 2017. Soldiers demonstrate their skills and tactics during a contract drill as they train to become part of the world's first all-female special forces unit, the Jegertroppen or “hunter troops”. (Photo by Carolina Reid/NBC News)

A marine rescue worker from Sea World works in a joint attempt with his colleagues to help a juvenile humpback whale stranded at Palm Beach on the Gold Coast, in Queensland July 9, 2014. (Photo by Jason O'Brien/Reuters)