Better sleep, powered by your body's cues
Learn when your body is naturally ready for sleep and when it's primed for activity.
Align with your thermal rhythm to fall asleep faster and wake up restored.
Join a community of people already in line for better sleep.
Better sleep, powered by your body's cues
Learn when your body is naturally ready for sleep and when it's primed for activity.
Align with your thermal rhythm to fall asleep faster and wake up restored.
Join a community of people already in line for better sleep.
A dual-wearable system for precise circadian timing
Developed in collaboration with leading sleep and circadian rhythm experts, Larcz tracks your body clock by reading how your heat signatures change through the day.
Know how to make the most of your day and night
Each morning, guided by your body clock, Larcz highlights the best times for natural light, movement, and sleep to help you feel more energized during the day and rest more deeply at night.
→ Discover your best times for focused work, exercise, and sleep
→ Get notified when it’s time to start winding down
→ See how consistently you’re aligning with your circadian rhythm over time
Learn the nuances of your sleep
Go beyond basic sleep tracking. Larcz reveals meaningful insights into your movement through the night, blood oxygen levels, and sleep debt, helping you make small, personalized adjustments for deeper, more restorative sleep.
→ Discover which sleep positions support your most restful nights
→ Identify dips in blood oxygen during sleep
→ See how much sleep your body needs to recover, and how to restore it over time
Decode the subtle shifts in thermal balance that occur while you sleep
Larcz tracks how your heat signatures change through the night, revealing signs of thermal imbalance that may affect sleep quality and recovery.
→ See how efficiently your body releases heat during sleep
→ Identify periods of thermal stress that may disrupt rest
→ Understand which changes support better thermal balance
Create a more restful sleep environment
Larcz monitors temperature and light in your bedroom to help you understand how your environment influences your rest.
→ Night-by-night room temperature and light tracking
→ Spot patterns between your environment and sleep quality
→ Long-term trends to guide better sleep habits
Two pods, worn together, enable accurate circadian and heat flow tracking
Wear one pod on your chest and one on your arm. The chest pod captures temperature signals from the core region, while the arm pod measures surface temperature changes.
Together, they reveal your thermal rhythm throughout the day, and night.
Built for comfortable wear, day to night
What is included
Larcz pods
Discreet, lightweight pods with a refined form factor designed for all-day and all-night comfort.
Smart dock
An elegantly designed dock that charges and protects your pods while quietly monitoring your bedroom environment.
Hypoallergenic patches
Ultra-soft, breathable patches engineered for secure, comfortable wear for up to seven days.
Charging cable
USB-C to USB-C charging cable for fast and reliable charging.
Who Larcz is designed for
Made for those who want better sleep, better days, and stronger performance
Understand what’s disrupting your sleep
Find out what’s interfering with your rest, from circadian misalignment to thermal imbalance.
Build daytime energy and wind down naturally at night
Align light, activity, and rest with your body clock to feel more energized during the day and ease into sleep more naturally at night.
Improve athletic performance
Optimize performance and recovery by aligning training and sleep with your body’s natural rhythms.
Latest insights
Science, stories, and strategies from the world of thermal performanceScience, stories, and strategies for better sleep and recovery
Mar 8, 2026
Is your sleep and fitness tracker misleading you?
Sleep, recovery, and performance are whole-body processes. Here’s why multi-zone tracking matters
Feb 15, 2026
Your clock is your superpower: How circadian rhythm drives better sleep and performance
Timing beats effort. When you train or sleep in sync with your body clock, everything becomes easier.
Jan 6, 2026
Unlocking the hidden language of heat for smarter sleep and training
Heat is your most honest performance metric—learn to read your thermal rhythm to train and recover smarter.
Common questions, clearly explained
Larcz is a dual-wearable system designed for continuous, everyday use. Larcz reads your heat signatures across key zones of your body throughout the day, building a thermal profile unique to you. From this, it reveals your body clock and readiness windows for sleep, recovery, energy, and performance, so you can time daily activities in sync with your circadian rhythm.
Interested in exploring thermal intelligence for performance and recovery?
Reach out to learn more about early access, partnerships, or media.