saavu
Heat. Cold. Thrive.

The watch-first app that proves
sauna is changing your body.

Track heart rate, HRV, and recovery through every round of heat and cold, right from your wrist. See your wellness as a face, not a spreadsheet. Find saunas nearby.

No phone needed

Your watch tracks everything during heat and cold. Leave the phone in the locker.

See your body respond

Heart rate, HRV, and recovery, updating in real time through every phase.

Find saunas nearby

Discover saunas, cold plunges, and contrast therapy spots wherever you are.

Your data, your proof

Everything your body tells you
during heat and cold.

Heart Rate

Real-time BPM during every phase: sauna, cold plunge, and rest. See exactly how your heart responds.

HRV

Heart rate variability: the gold standard of recovery measurement. Track how sauna improves it over time.

Skin Temperature

Monitor how your body thermoregulates through heat and cold exposure using your watch sensors.

Recovery Score

Post-session wellness measurement combining HRV, heart rate recovery, and personal baseline comparison.

Session Streaks

Build consistency and see the compound effect. Your body improves most when the habit sticks.

Sleep Impact

Correlate sauna days with sleep quality. Most users see 20–40 minutes of improved sleep on sauna days.

How it works

From start to finish.
Saavu tracks it all.

1

Enter

Walk in. Tap start on your watch. That's it. No phone, no fuss.

2

Track

Heart rate, HRV, and rounds. All recorded automatically through every phase.

3

Cool

Switch to cold plunge. Saavu tracks your recovery and HR drop in real time.

4

Review

See your face state, session stats, and how this session compares to your baseline.

See it in action

Designed for the sauna.
Built for your wrist.

9:41● ●●●●
Good evening, Tom
Thriving today
HRV up 23ms vs your baseline
Sessions
4
Avg Duration
38m
Last HRV
62ms
Wellness
78
This week
7 day streak
Keep the smoke alive
7
Home
9:47● ●●●●
Round 3 · Sauna
12:43
142
BPM
Melting nicely
Sauna · Cold · Sauna · Cold · Sauna · Cold
Active Session
9:41● ●●●●
s
Nordic Spa is nearby
0.3mi away · Open now
now
All
Finnish
Cold Plunge
Steam
Nearby
Nordic Spa
0.3mi · Open now
Finnish
Cold
The Bathhouse
1.2mi · Open until 22:00
Steam
Sauna
Discover
saavu
Apple Watch + Wear OS
saavu
Last session
Yesterday · 42m
7 day streak
Start session
Idle
Round 3 · Sauna
142
BPM
Melting
12:43
Active
Session complete
Thriving
HRV+23ms
Peak HR156
Summary
The face states

Your recovery shown as a face,
not a spreadsheet.

Tense
Pre-session
Melting
In the sauna
Refreshed
After cold
Thriving
Post-session
Peak
Best day ever

Saavu translates complex biometrics into something instantly readable. No charts required. Just look at your face. It changes in real time as your body responds to heat and cold.

Personalised insights

The longer you use Saavu,
the smarter it gets.

Your HRV rises 23ms on sauna days.

Based on your last 30 sessions

You sleep 34 minutes longer after evening sessions.

Compared to non-sauna days

Best recovery this month: Tuesday's 3-round session at Nordic Spa.

HRV peaked at +31ms above baseline

Insights generated from your own data after 10+ sessions. No guesswork, just your body's story.

The smoke arrives. Your body changes. Saavu remembers.

Savu is smoke, the soul of the sauna. Saavu is to arrive. Together they describe what the product does: it meets you where you are, and shows you how your body is changing.

Coming soon to Apple Watch
and Wear OS.

Track your sauna sessions. See the proof. Find your next venue.

Join the early access list. Launching 2026.