19 January 2011
Last updated at 14:09
Most Orthodox Christians, like this man in the central Russian village of Velikoye, celebrate the Feast of the Epiphany on 19 January because they follow the Julian Calendar. The man shown here is bathing in an icy pond to mark the baptism of Jesus Christ.
For Western Christians, the Epiphany marks the coming of the Magi - the Three Wise Men - to see the Infant Jesus. But for Eastern Churches, it is about his baptism in the River Jordan and all water on Earth may be regarded as "holy water" during the feast.
The idea is that bathers symbolically wash away their sins but some also argue that a dip in freezing water is as good as a tonic. Bathers in Velikoye, like this young woman, seemed to be enjoying themselves. But doctors question the wisdom of ice-dipping.
A report in Russian newspaper Pravda (english.pravda.ru) says Epiphany in Russia has become a busy time for doctors and rescuers. Only people already in good health, it says, will feel better after bathing in ice-holes, such as this one in Velikoye.
Russian bathers traditionally go under the water three times. This photo was sent to the BBC Russian Service from Moscow by blogger bulbashov.
Another image sent by bulbashov captures the terrific shock to the system of an Epiphany dip.
Here a woman is reflected in the icy water as she prepares to enter Lake Razliv in the town of Sestroretsk, 30km (18m) north-west of St Petersburg, Russia's second city.
Orthodox Christians in neighbouring Belarus, like this man in Minsk, have also been bathing in crucifix-shaped ice holes.
In the milder climate of Serbia, men dive into a lake in Belgrade to retrieve a special crucifix.
The crucifix was partially fashioned from ice.