The pair beat off competition from Americans, Germans and Turks to clinch the title of who can sit the longest in heat of 110 degrees Celsius (230 Fahrenheit).
Timo Kaukonen won the male championship for the third year in a row because he was able to stand the heat for an incredible 12 minutes 26 seconds.
Leila Kulin struck gold sitting for 10 minutes and 31 seconds, almost two minutes better than her closest rival, another Finn. The pair had a bit of an advantage. The sauna began life in Finland more than a thousand years ago and is now as internationally well-known as a product of that northern European country as the Nokia mobile phone.
The world championships in sauna sitting have been held in Heinola, 90 miles north-east of Helsinki, since 1999. Sauna's are a key part of Finnish life and some even like to relax in the steam with a beer. They are now popular in most health clubs across the UK and the world.
Many websites claim that the sauna can be just as beneficial as having a full gym workout . They also claim that the sauna sweats out impurities found beneath the skin.
There are 1,212,000 saunas in private apartments in Finland. With another 800,000 installations in summer cottages and public swimming pools that makes for more than two million of them for a population of 5.2 million.
Visit http://cankar.org/sauna/index.html to find out more about the Finnish sauna.