Descending into the Marum Volcano in Vanuatu, Intrepid explorers found an unusual way of staying warm this winter by spending Christmas day on an active volcano. British climber Chris Horsley, 22, and his friends Gareth Hawken, 30, Geoff Mackley, 50, and Bradley Ambrose, 36, from Auckland, New Zealand, hiked up the Marum Volcano, Vanuatu, on the morning of the 25th. Instead of passing the day with their families, the team climbed down a 1200ft cliff to get close to a flowing lake of lava. (Photo by Bradley Ambrose/Caters News)

A 13-month-old chimp named Fumo carries a “Christmas present” of food treats in wrapping paper under his arm during a Christmas-themed feeding time at Sydney's Taronga Park Zoo, December 9, 2014. Fumo, meaning “chief” or “spear” in Swahili, is one of the latest additions to the zoo's successful primate breeding program. (Photo by Jason Reed/Reuters)

A worker heats a glass cat-shape ornament at the Silverado manufacture of hand-blown Christmas ornaments in town of Jozefow outside Warsaw December 2, 2014. (Photo by Kacper Pempel/Reuters)

Children pose for photographs with the Dream Toys predicted Top 12 toys for Christmas during the Dream Toys 2007 Christmas predictions fair on October 10, 2007 in London, England. (Photo by Daniel Berehulak/Getty Images)

Dancers Amy Hadley and Bethany Kingsley-Garner from the Scottish Ballet wait backstage during the dress rehearsal of the current production of “Sleeping Beauty” at the Theatre Royal on December 16, 2011 in Glasgow, Scotland. (Photo by Jeff J Mitchell/Getty Images)

As a social experiment, journalist Esther Honig contacted Photoshop artists across the world and told them to make her beautiful, and they did. Honigh said she was surprised by how her image was altered, saying the process has greatly changed her perception of beauty. Photo: “Before & After” project: Greece. (Photo by Esther Honig)

A giant ham bread, a typical Venezuelan Christmas dish, is seen on a table during an attempt to break the Guinness World Record for the biggest ham bread, in Caracas November 15, 2014. The giant hallaca more than 120 metres long. (Photo by Carlos Garcia Rawlins/Reuters)

Revelers dressed as Santa Claus or in festive costumes arrive for the start of SantaCon 2018 in New York City December 8, 2018. SantaCon is an annual event where people dress as Santa Claus or other Christmas characters parade in several cities around the world. (Photo by Timothy A. Clary/AFP Photo)