The sauna marathon is based on the principles of orienteering, with teams of four needing to track down and enter every designated sauna in as quick a time as possible. All team members need to be fully inside each sauna for a minimum of three minutes to qualify for marking that particular sauna off, as well as any ice holes and hot tubs which they encounter.

In recent years the total number of saunas in the marathon has been around 20.

Some changes to the rules since previous years have made the event even more competitive.

''This year we are giving the participants orienteering chips – this helps us better to get the final results in and is more comfortable for them,'' said Otepää Cultural Center Jorma Riivald.

"The number of participants – last year more than 900 people – demonstrates the great interest in this event, and not only in Estonia. We are very glad to host all the sauna aficionados,'' Mr Riivald went on.

For those who want to enter the event, registration opens at 09.00 EET at the Otepää Cultural Centre and the marathon itself starts at 12.00. Four-member team tickets cost €70 (these can be purchased from 4 January here) and competitors are also required to have a €35 deposit for the tracking wristband which each team must wear. Teams registering late can partake in the even but will not be included in the rankings, being listed as ''enjoyers'' instead.

The event lasts until 17.30, and a poll of the favourite sauna is to be taken from all the competing teams.

Otepää recently hosted the Estonian ski championships, and is also due to host a round of the world cross-country skiing championships in January.