The cold doesn't seem to be a problem for these women who dance on December 02, 2020 in Cardiff, Wales. From Friday at 6pm licensed pubs, cafes and restaurants in Wales will have to stop serving alcohol and close at 6pm every day until further notice. The regulations will be reviewed on 17 December. The rules follow a firebreak period which started on October 23 and ended on November 9 which saw all non-essential shops close. (Photo by Huw Evans Picture Agency/The Sun)

Hannah Maule-ffinch, “Wild Swimmers”, 2020, Hinksey Lake, Oxfordshire. Category: People. The series Wild Swimmers explores how humans are strongest when coming together in the face of adversity. In this photo, Emma and Emma have an amazing bond and friendship, built through their daily ritual of cold swimming in often bracing conditions. (Photo by Hannah Maule-ffinch/Earth Photo 2022)

Tourists photograph a red dear stag visiting a car park near Glen Coe on December 1, 2017 in Glen Coe,Scotland. On the first day of the meteorological calendar, the UK was experiencing slightly warmer temperatures today with weather forecasters indicating that the recent cold spell is almost over. Yesterday's snow across eastern parts of England is expected to melt away over the course Friday as temperatures start to rise. (Photo by Jeff J. Mitchell/Getty Images)

A man bundled up for the cold weather carries a dog in his jacket while walking along the waterfront in New Westminster, British Columbia, Tuesday, December 28, 2021. Environment Canada has issued an arctic outflow warning for Metro Vancouver and the south coast with well below normal temperatures forecast for the region. (Photo by Darryl Dyck/The Canadian Press via AP Photo)

A child dressed as an Ewok character participates in a Star Wars parade in Mexico City, Saturday, October 15, 2022. (Photo by Marco Ugarte/AP Photo)

“Contrails (short for “condensation trails”) or vapour trails are artificial clouds that are the visible trails of condensed water vapour made by the exhaust of aircraft engines. As the hot exhaust gases cool in the surrounding air they may precipitate a cloud of microscopic water droplets or, if the air is cold enough, tiny ice crystals”. – Wikipedia

Photo: An airplane leaves a vapor trail as it flies in front of he moon on January 17, 2007 above Hanover, Germany. (Photo by Alexander Hassenstein/Getty Images)

A pheasant stands in snow near Dulverton on January 30, 2012 on Exmoor, England. After unseasonably mild winter weather, some parts of the UK woke to a covering of snow as a cold spell of weather sets in, with forecasters warning temperatures are set to plunge as the week progresses. (Photo by Matt Cardy/Getty Images)

A man uses a snow blower to clear a sidewalk during a winter storm ahead of the Christmas Holiday outside the Union Station, in Chicago on December 22, 2022. More than 2,200 flights were canceled across the United States by Thursday afternoon as a massive winter storm named Elliot upended holiday travel plans with a triple threat of heavy snow, howling winds and bitter cold (Photo by Kamil Krzaczynski/AFP Photo)