Evidence review
How long should you stay in a sauna?
Forty-five minutes of infrared moved core temperature by 0.0°C. Thirty minutes of hot sauna moved it more. What the duration research shows—and how to use a timer well.
iPhone · Apple Watch
Guided sessions for every kind of heat.
Heatspace runs your sauna, infrared, steam, hot bath, or red light session as timed phases — from the first minute of heat to the last of the cool-down.
Free rituals included · No account required
9:41
Phase 1 of 2
19:44OF 20:00
Continuous Sauna
78 °C · heart rate 118
Voice cue · 15:00
Fifteen minutes in. Five minutes remain, but there is no need to stay for a research marker.
SAUNA
19:44Built forTraditional saunaInfraredSteam roomHot bathRed light
The library
Pick a shape, not a number.
Twenty-eight rituals across the five practices. Each one is a typed sequence of phases — heat, rest, cool-down — with its own pacing, cues, and temperature behaviour. A plain countdown can only tell you when it ends.
Browse every ritual9:41
Rituals
Beginner Sauna10 MIN
Gentle · one phaseExercise + Sauna 1520 MIN
Medium · heat, then coolFrequent Sauna 2025 MIN
Medium · heat, then coolThe record
Numbers you can’t fail at.
Every figure is measured against your own history, or against a scale the app already defines — never a target, never other people. When an input is missing, the track goes dashed instead of pretending the score was complete.
How the timer records a session9:41
History
Active weeks
31of 52 weeks observed
Your usual is about four sessions a week.
Average heat load
47of 100 · moderate
A steady heat load across the year.
Sessions with all four inputs
9of 24 scorable
Heart response is the input missing most often.Evidence zones
Every marker names its own limits.
Where a duration is backed by a specific study, Heatspace shows that study’s design, population, and protocol alongside it — including the trials that found nothing. Where the evidence rests on something the app cannot measure, it shows no marker at all, and says why.
How we read the research9:41
Frequent Sauna 20
Association only
20 minutes matches the long-session category in Finnish cohort research.
This is an association, not a target. Cool-downs and split rounds are never added to it.
Why no marker on some rituals
Where the evidence depends on something Heatspace cannot measure, it shows none.
Also in the app
The rest of it.
Lock Screen and Dynamic Island
Time left, the current phase, and temperature — without unlocking anything.
Apple Watch
Run the whole session from your wrist. It saves once, even if your phone was running too.
Apple Health
Finished sessions save as workouts, with duplicate protection.
Voice cues
Spoken prompts at the moments that matter, in a minimal or fuller mode. Turn them off and nothing speaks.
Your own rituals
Build a phase sequence with your own durations and temperatures, and save it alongside the rest.
Heat Load
One score out of 100 from duration, temperature, heart response, and how hard it felt.
On your device
Nothing here needs an account.
- Sign in only if you want Pro to follow you onto another device. The rituals, the timer, and your history work without it.
- No cross-app tracking and no advertising identifiers, in the app or on this site.
- The app asks for no location access at all.
- Apple handles the payment. Heatspace never sees your card.
Questions people ask first.
Do I need a real sauna?
No. Heatspace runs traditional sauna, infrared, steam room, hot bath, and red light sessions, each with its own temperature range, pacing, and safety notes.
Can I leave my phone outside the room?
Yes. The Apple Watch app runs the whole session from your wrist, and a session that ran on both saves to Apple Health only once.
What do I get for free?
Every practice has one free ritual — Beginner Sauna, Infrared Gentle Start, Steam Gentle Reset, Evening Soak, and Simple Light Session — along with the timer, the record, and Apple Health saving. Pro unlocks the other two in each practice and custom rituals.
How does it decide what counts as evidence?
Only a specific study can put a duration marker on a ritual, and the marker carries that study's design, population, and protocol — including trials that found nothing. Cool-downs and split rounds are never counted toward it.
Is Heatspace medical advice?
No. It is general wellness guidance. It never asks you to stay in the heat to reach a marker, and it tells you to leave if you feel unwell.
From the Heatspace Journal
Research you can actually use.
Evidence review
How often should you use a sauna?
The 4–7 sessions per week figure comes from one group of Finnish men. Here is what those studies measured, what a randomized trial found, and how to pick a rhythm.
Evidence review
Steam room vs sauna: what the research actually shows.
A research-led comparison of steam rooms and dry saunas, including humidity, heat strain, practical protocols, safety, and the limits of current evidence.
Find your space in the heat.
Guided rituals across five practices, on iPhone and Apple Watch.
Free rituals includedPro $4.99/month$29.99/year$49.99 lifetime (CAD)
Heatspace is general wellness guidance, not medical advice. It never asks you to stay in the heat to reach a marker. Follow your facility’s rules, and leave immediately if you feel dizzy, faint, or unwell.
HeatspaceFree rituals included