Contrast Therapy: Sauna & Cold Plunge

Elevate your thermal recovery with Contrast Therapy -- the dedicated, silent tracker built specifically for sauna, cold plunge, and autonomic nervous system conditioning. Designed for athletes, biohackers, and recovery enthusiasts who demand deep physiological data without disruptive beeping in quiet spa environments. KEY FEATURES SAUNA AND HEAT PROTOCOL * Custom heat duration countdowns (default 15:00) * Live Cardiovascular Heat Load (Peak HR, Zone metrics) * Hardware Thermal Safety Guard: Continuous internal chassis temperature monitoring with automatic emergency vibration warnings if device temp reaches 44.0 degrees Celsius. ICE BATH AND COLD PLUNGE * Cold immersion timer (default 3:00 / 5:00) * Vagal Tone and Parasympathetic Tracking: Automatically captures your Minimum HR in the ice. SMART TRANSITION BUFFER * 1-minute transition shower countdown ensures watch casing normalizes to ambient room temperature before ice immersion, protecting waterproof seals. AUTONOMIC NERVOUS SYSTEM TELEMETRY * Autonomic Flexibility Score (Delta HR): Calculates your heart rate spread (Max Heat HR - Min Ice HR) to measure autonomic resilience. * Multi-Round Support: Seamlessly log Round 1, Round 2, and Round 3. 100% SILENT HAPTIC CONTROL * Zero beeping or loud alarms. Customized tactile vibration pulses notify you when targets are reached without disturbing others in the recovery area. * Zero auto-advancing: Full manual control via physical button presses. GARMIN CONNECT SYNC Automatically logs custom Developer FIT Fields into your Garmin Connect activity summary and charts: * Sauna Time and Peak Heat HR * Cold Plunge Time and Minimum Ice HR * Peak Watch Temperature (C) * Autonomic HR Delta * Total Completed Rounds HARDWARE COMPATIBILITY Optimized for high-resolution Garmin AMOLED displays (Forerunner 965, 970, 265, Fenix 8, 7 Pro, Epix 2, Venu 3, Vivoactive 5, 6) with true black battery-saving backgrounds.

Initial official release of Contrast Therapy. - Full multi-round state machine: Sauna to Transition Shower to Ice Bath to Rest. - Real-time watch chassis temperature safety monitoring. - Autonomic Flexibility (Delta HR) calculations and Garmin Connect FIT developer metrics. - 100% silent haptic vibration patterns.