Sauna and plunge modes
Track either side of the session with large, glanceable timers and clear mode colors.
Apple Watch app
Phyros
A clean sauna and cold plunge timer that keeps your rounds, transitions, heart rate, and recovery rhythm on your wrist.
Built for contrast sessions
Less fiddling, more flow.
Phyros is made for people moving between heat and cold. Start a session, switch modes when you move, feel the haptic cue, and finish with a simple summary of time spent in sauna and plunge.
What it does
The essentials, right where you need them.
Fast transitions
Tap once when you move between heat and cold, then confirm when you arrive.
Heart-rate context
With permission, Phyros reads heart rate during a workout session and shows average and peak BPM.
Hydration cues
Optional sauna exposure reminders help you keep water top of mind during longer heat blocks.
Screenshots
Designed for quick checks mid-session.
Support
Need help with Phyros?
Email admin@mstep.nz and include your Apple Watch model, watchOS version, and a short description of what happened.
Heart rate is not appearing
Check that Phyros has permission to read heart rate in Apple Health, then start a new session. Heart-rate data may take a few moments to appear after the workout begins.
The app is asking for Health access
Phyros uses HealthKit to read heart rate and save the watch workout session. You can change access at any time in the Health app settings on your iPhone.
Can I use only sauna or only plunge?
Yes. Start the session with the mode you need and use the mode controls only when you want to switch between heat and cold.
Privacy
No account, no tracking scripts.
Phyros does not require an account. The app only requests HealthKit access needed for heart-rate display and workout session handling. This support website does not include analytics, advertising, or third-party tracking scripts.
Phyros is for wellness tracking and timing only. It is not a medical device and does not provide medical advice.
Read the full Privacy Policy