Name: Sauna n Cold Plunge
Author: SaunaNPlunge

Sauna 'n Cold Plunge turns your contrast-therapy session into a proper mini workout on your Garmin.

Press START when you begin and tell the watch where you're going next: Heat, Shower, Water, Breathe or Rest. One press each time you move. That's it. No prescribed routine, no timers you have to follow - the session runs from your first press to your last, whether that's two minutes or two hours. Sauna, steam room, onsen, cold shower, ice bath, cool pool or the sea: it works the same way everywhere.

WHAT THE WATCH DOES
- Times every phase and your whole session
- Tracks heart rate through each phase: peak in the heat, heart rate going into the water and coming out, how far it dropped and how fast (bpm per minute)
- Counts your hot-to-cold cycles
- Lets you type in the water (and optionally heat) temperature from your thermometer, because hands usually stay out of the ice bath
- Reads the watch temperature sensor too, so you can compare
- Estimates calories and fluid loss
- Optional heart-rate alerts (high and low limits you set)
- Shows a per-phase summary on the watch when you finish

WHAT YOU GET IN GARMIN CONNECT
Each session saves as a Cardio activity. Every phase is a lap, so you can see heat time, cold time, temperatures and heart-rate response in Connect, and the session carries extra fields: cycles, heat time, cold time, biggest HR drop, peak HR in heat, estimated fluid loss.

WHY THE BUTTON PRESSES?
A watch can't reliably tell a sauna from a hot shower, or an ice bath from a cold sea, and sensor temperature lags by minutes. One press from you is faster, more accurate and keeps you in charge. The app never guesses your phase.

SAFETY
Heat and cold immersion put real stress on the heart and circulation. Go gradually, never alone, and get out at the first sign of dizziness, numbness or chest discomfort. This app is not a medical device and gives no medical advice. Talk to your doctor before contrast therapy if you have a heart condition, high or low blood pressure, are pregnant or have any other health concern. Calorie and fluid-loss figures are estimates only.

Free. No account, no subscription, no data leaves your watch except the activity you choose to save.