Some 1,000 swimmers from all over the world have gathered at the lakeside town of Bled to take part in the 13th Winter Swimming World Championships this week. The oldest among them is about to turn 88.

The participants come from 31 countries, most of them from Finland, the UK, Germany and Denmark, but there are also swimmers from Argentina, Mongolia and Morocco.

"Winter swimming has crossed the borders of cold climate countries and has become a global sport," Urška Klinar from Si Sport, the company organising the event, said.

Former Olympian Luka Turk is among the ten Slovenian swimmers who have registered for the event, which will feature a total of 17 disciplines, 12 of which competitive.

After a day of test swims, the championship will get under way on 24 January with the Bled Swim, a 1,000-metre distance swim that is only fit for the toughest.

Everyone brave enough can take a dip or a dive in the lake and take part in no-timing freestyle swims of between 25 and 50 metres. There will be group swims and international relays.

The weather is a key factor in the competition and it is important that the water is not too warm, especially for those going for top results and records.

When Bled first hosted the championships in 2020 the problem was too high temperatures and during earlier World Cup events ice had to be cut out from the frozen lake to make swimming possible.

Klinar says the water is supposed to have between 3 and 5 degrees Celsius. At this time the lake water temperature is at the upper limit, but the snow has created a lovely backdrop.

Under the rules, swimmers can only wear goggles, a decent bathing costume and a swim cap made of latex or silicone. Neoprene is not allowed.

Once out of the water, they will have sauna, jacuzzi and a cup of hot tea to warm them up.

Back in 2020, the championships attracted more than 1,100 participants to Bled. This time the Alpine resort is hosting the event instead of Russia's Petrozavodsk.