Frequently Asked Questions

Plunge supports 7 thermal wellness environments:

• Dry Sauna — Traditional dry heat sauna
• Steam Room — High humidity steam environment
• Infrared Sauna — Infrared panel sauna
• Hot Tub — Hot water soak (90+°F)
• Cold Plunge — Cold water immersion (sub-70°F)
• Cold Shower — Cold water shower
• Red Light — Red light / near-infrared therapy

Each environment has a tailored thermal dose multiplier and is categorized as Heat, Cold, or Light for weekly target tracking.

The depth gauge and water temperature sensor are exclusive to Apple Watch Ultra and Ultra 2. These features automatically detect water submersion and provide live depth and temperature readings during cold plunge and hot tub sessions.

All other Apple Watch models (Series 5+) provide full heart rate, HRV, and workout tracking. You simply won't get automatic water detection and temperature — you can select your environment manually instead.

Every session earns XP based on:

• Base: 10 XP per completed session
• Duration: Up to 30 bonus XP based on session length
• Environment: Multiplier varies (steam 1.3x, infrared 0.8x, etc.)
• Streaks: Up to 50 bonus XP for consecutive daily sessions
• Contrast: +15 XP for multi-environment sessions

There are 10 levels from Initiate (0 XP) to Legend (5,500 XP) and 13 milestone achievements including first session, 10th session, 100th session, streak milestones, and trying each environment type.

Contrast sessions let you switch between heat and cold environments within a single workout. For example, you might alternate between a dry sauna and a cold plunge.

Plunge tracks each segment separately within the session, recording environment type, duration, and heart rate for each segment. Contrast sessions earn a +15 XP bonus.

Yes. Plunge is built on a local-first architecture:

• All session data is stored on your device only
• HealthKit data never leaves Apple Health
• No user accounts or personal data collection
• WatchConnectivity syncs data only between your own paired devices
• Analytics (PostHog) are anonymized with no personal identifiers
• Crash reports (Sentry) contain no health or personal data

Read our full Privacy Policy for complete details.

Yes. Plunge has a companion Connect IQ app for Garmin watches including Fenix 7/8, Forerunner 255/265/965, Venu 3, Enduro 2/3, and epix Gen 2/Pro.

The Garmin app provides full session tracking with environment selection, heart rate monitoring, FIT recording, and box breathing overlay. Sessions sync to the Plunge iPhone app via Connect IQ Communications.

Plunge offers core session tracking features for free, including environment selection, timer, heart rate tracking on Apple Watch, and basic session history.

Premium features (available via monthly or annual subscription through the App Store) include advanced analytics, health trend charts, extended session history, and additional breathwork patterns.

Yes. Plunge supports iPhone-only sessions using ambient sensors:

• Microphone: Real-time sound classification to detect your environment
• Barometer: Pressure sensing for sealed room detection
• AirPods: Head motion data for stillness tracking (AirPods Pro/Max)
• WeatherKit: Outdoor temperature and humidity for context
• Passive HR: Background heart rate from Apple Watch if paired

Apple Watch provides the richest experience, but iPhone sessions are fully functional.

You can export all session data as a JSON file from the app. This includes your complete session history with environment types, durations, heart rate data, thermal dose calculations, and XP progress. The export is designed for data portability and personal backup.