They’d summitted great peaks. They’d scuba-dived in some of the world’s most dangerous seas. Suspended hot tubbing was clearly the next step.

Thierry Bieler, Jean-Christophe Boillat, Pierre Cauderay, Dominique Weibel and Nicolas Weibel are leaders of  a group of extreme hot tubbers with a long history of pulse-pounding achievement.

While soaking at great height is their latest feat, the last 10 years have seen a regular succession of hot tub projects for the group. From tubbing in the middle of a lake, to doing it deep in a cave, they never work on a boring project.

To that end, on Oct. 1, 2011, the group successfully suspended a hot tub from Gueuroz Bridge in Switzerland. Gueuroz Bridge is one of the highest bridges in Europe with 600 feet of extremely non-supportive air between the span and the ground. The hot tub was hung a mere 130 feet below the bridge, leaving the group of 23 people with the distinct possibility of a rapid 470-foot descent should any one of them slip on wet acrylic near the spa’s edge.