Bathing in freezing weather in unheated open waters on Epiphany is one of the most popular religious rites among Russians, with more than 2.1 million people participating annually, according to reports.
According to long-standing beliefs supported by scientific observations, the day of Epiphany is one of the coldest days of the year in most of Russia, where the temperature in parts of the country can sometimes reach negative 30 degrees Celsius (-22 Fahrenheit).
And even the pandemic has not stopped believers from swimming in extremely cold weather in unheated open water bodies, such as lakes, ponds and rivers.
The vast majority of Russians who plunge into frozen water, where the temperature is typically no higher than 4 degrees Celsius, submerge themselves at least three times.
Even children and senior citizens take part in the Epiphany ritual.
Swimming in ice water can be a serious shock for an unprepared body, so local authorities usually prepare and designate places where one can bathe. Also, during the ceremony, emergency services are on duty nearby, in case someone needs help.
Foreigners have also been known to participate in the ritual, wishing to test themselves or take part in the Russian tradition. According to social media, this year a German blogger visited the village of Oymyakon, located in Yakutia beyond the Arctic Circle and considered one of the harshest permanently settled places on Earth. The temperature there on Epiphany was minus 42 degrees Celsius.
Last year, Angolan cadets at a military academy in the Russian Far East took part in the ritual, even though the temperature that day did not exceed minus 25 degrees Celsius. As the cadets explained to Russian journalists, at first it was scary, and then they got used to the water, even saying, "It's normal, it's warm".
Traditionally, Russian President Vladimir Putin also takes part in the bathing ritual, although he has yet to announce whether he did it this year.
Although the feast is traditionally held on 6 January, some countries in Eastern Europe whose churches still use the Julian calendar celebrate the feast on 19 January.
The ritual, which began in Russia presumably in the Middle Ages, is intended to mark the baptism of Jesus Christ in the River Jordan. To commemorate this, holes in the ice of rivers, lakes, and other bodies of water are cut usually in the shape of a cross.