We read sauna and cold plunge claims against the research
We put every claim about heat and cold on the dial.
Podcasts and ads promise a lot from a hot room and a cold tub. We trace each promise back to the study it came from and show you how far it drifted on the way.
96°H · Hot air
“Infrared sauna sweat is 20% toxins, where a normal sauna's is only 3%.”
Read the verdict →Each ladle reads another claim
The board
Every claim lands somewhere between solid and hot air
Each dot is one claim at its reading, with the heat claims above the line. Hover or tap a dot to read it, then open it for the studies behind the number.
- Solid 1
- Likely 7
- Early 16
- Stretched 18
- Hot air 12
Swipe along the scale
TLDR
The ideas that hold up fit on one page
Stories
Scroll through the studies behind the headlines
Story · Heat
Watch the verbs heat up as a sauna study becomes news.
The 2015 Finnish sauna paper found frequent sauna use was associated with fewer deaths. Scroll through the week of coverage that followed and watch each headline climb a ladder of verbs toward a promise.
7 min readStart scrolling →
Story · Heat
Meet the 2,315 Finnish men behind the sauna longevity headlines.
The best-known sauna study followed men from one Finnish town for more than twenty years. Scroll through the cohort one ember at a time and see where its famous numbers come from.
6 min readStart scrolling →
Story · Cold
Most cold plunge rules come from studies that kept people cold for hours.
Cold plunge advice leans on a few famous numbers. We traced each one back to its study and plotted every study by how cold it got and how long each session lasted.
8 min readStart scrolling →
Solid ground
These claims hold up best
How we rate
Four questions set every reading on the dial
Each question adds up to 25 degrees of hype. A claim reads near zero when strong, repeated human trials back it in the same words it uses.
Read how we rate claims →01 · Evidence
What kind of evidence exists in people?
02 · Consistency
Has the finding held up?
03 · Magnitude
Does the claim match the size of the effect?
04 · Dose
Does the studied protocol match how people use it?
- claims on the dial
- 54
- studies explained
- 56
- interactive stories
- 4
- sources cited
- 391
From our sister magazine
Sauna Monthly compares the saunas and plunge tubs worth buying
When you're ready to build a sauna or buy a tub, our sister magazine compares the prices and specs across every brand it reviews.
Sauna Monthly · Shop
These outdoor saunas reach Finnish temperatures
Sauna Monthly compares barrels and cabins that run hot-rock heaters.
Sauna Monthly · Guide
These cold plunge tubs are worth buying
Sauna Monthly picks its favorites and names the spec that decides between them.
Nootka Saunas
Nootka 8ft Barrel Sauna
Almost Heaven
Almost Heaven Salem 2-Person Barrel
Ice Barrel
Ice Barrel 500
Sun Home Saunas