21 Researchers Work Toward Common Standards for Sauna Science

A sauna study’s headline may tell you how long people sat in the heat. It may tell you much less about the steam, the cooling breaks or how often they came back. Those details make a difference when comparing one study with another, or with your own sauna routine.

The Sauna Research Foundation is tackling that problem with a working group of 21 researchers from 14 institutions in nine countries. Its Oslo initiative, organized around a September 22–24 symposium at The Well, aims to establish shared definitions and a checklist for reporting heat-therapy studies. A peer-reviewed consensus publication is expected in 2027.

What happened inside the sauna?

The proposed checklist covers temperature and humidity, time in the heat, frequency of sessions and the type of heat exposure. Researchers would also describe the length of the study and how the heat exposure changed over time, according to the foundation’s September 23 announcement.

Consider two sessions with the same total time in the sauna: one continuous sit and several shorter rounds with cold-water breaks. Recording only the minutes obscures the difference. Bangor University’s research into sauna rounds and cooling explores this same gap between how people bathe and how studies describe it.

Better reporting would help an operator judge whether a study resembles the sessions offered at their venue. It would also help a reader check whether the research behind a health claim actually tested the type of sauna they use.

One vocabulary, distinct forms of heat

The project covers sauna, infrared, hot-water immersion, hammam and balneotherapy. Clear labels are particularly useful when infrared and traditional sauna appear together in discussions of health benefits: a finding about one form of heat exposure cannot simply be assumed to apply to another.

Earric Lee of the Montreal Heart Institute is stewarding the study; Ashley Mason of the University of California, San Francisco, is steering committee co-chair. The team plans to put proposed statements through repeated review by an external panel of 30 to 40 researchers and clinicians, with an 80 percent agreement threshold.

The resulting document is intended to improve how research is conducted and reported. Recommendations for how long or how often to sauna are not yet an outcome of this work.