Hundreds of hardy swimmers across Britain braved jumping into freezing cold waters for a annual Christmas Day dip on December 25, 2017. (Photo by Dave Nelson/The Sun)

An Iraqi Muslim woman walks past Christmas decorations for sale in the Shiite holy city of Najaf on December 17, 2015. (Photo by Haidar Hamdani/AFP Photo)

Swimmers prepare to take part in the annual Christmas Day Peter Pan Cup handicap race in the Serpentine River, in Hyde Park, London, December 25, 2015. (Photo by Andrew Winning/Reuters)

Christmas baubles shaped as Santa Clauses wearing protective masks are pictured amid the coronavirus disease (COVID-19) pandemic in Eichenau, Germany, November 26, 2021. (Photo by Michaela Rehle/Reuters)

Aubrey Zimmermann, 9-months-old, poses for a photo with Santa at the Willow Grove Park Mall ahead of Christmas in Willow Grove, Pennsylvania, U.S. December 3, 2021. (Photo by Hannah Beier/Reuters)

A Palestinian man dressed as Santa Claus gestures as he rides a camel in Jerusalem's Old City during Christmas celebrations, on December 23, 2021. (Photo by Ahmad Gharabli/AFP Photo)

Swimmers in fancy dress take part in a Christmas Day dip at Exmouth, Devon, England, Saturday, December 25, 2021. (Photo by Ben Birchall/PA Wire via AP Photo)

In a north London hospital, scientists are growing noses, ears and blood vessels in the laboratory in a bold attempt to make body parts using stem cells. It is among several labs around the world, including in the U.S., that are working on the futuristic idea of growing custom-made organs in the lab. (Photo by Matt Dunham/AP Photo)