# CircadiaOS

> CircadiaOS is an iPhone app that turns the smart thermostat and wearable you already own into an automatic overnight bedroom temperature schedule. It cools the room for deep sleep and warms it before you wake, then runs one-variable-at-a-time experiments against your own sleep data to refine that schedule. No new hardware. Made by CircadiaOS LLC (Washington, DC area). Available in the United States on the App Store.

Key facts:
- Works with Apple Watch, Oura Ring, Whoop, Garmin and Fitbit (wearables) and Nest, ecobee, Honeywell, Sensi and other Wi-Fi smart thermostats.
- Two plans. Free: a starting schedule from your profile, optional wearable, nightly sleep data, no thermostat control. Premium ($12.99/month or $99.99/year): runs the four-phase schedule on your thermostat every night, with 14-night calibration and personalization from your wearable's sleep data.
- The schedule has four phases (pre-sleep, early night, late night, pre-wake) and is sent to the thermostat before bed, not adjusted in real time overnight.
- 14-night calibration on a fixed conservative schedule, then personalization that changes one setpoint at a time and holds it for 7–14 nights.
- Default operating range 63–70°F, with a user-set floor and ceiling.
- Support: support@circadiaos.com. App Store: https://apps.apple.com/us/app/circadiaos-app/id6761959749

## Pages

- [About](https://circadiaos.com/about/): CircadiaOS LLC was founded by athletes from the Washington, DC area who wanted overnight temperature control without buying another piece of hardware. Meet the team and read the mission.
- [App](https://circadiaos.com/app/): A tour of the CircadiaOS iPhone app: tonight's four-phase temperature schedule, sleep scores, night detail, history calendar, and thermostat connections. Requires iOS 18 or later.
- [Best temperature for sleep](https://circadiaos.com/best-temperature-for-sleep/): Most sleep research points to a bedroom of roughly 60–67°F (15–19°C), with about 65°F a common sweet spot. But the ideal is a curve: cooler as you fall asleep, lowest during deep sleep, warmer before you wake. Here is the biology and how to follow it automatically.
- [Chilipad alternative](https://circadiaos.com/chilipad-alternative/): Chilipad and Sleepme Dock Pro cool the bed with a $1,600+ water pad you refill and clean. CircadiaOS cools the whole room automatically through the smart thermostat you already own, for $99.99 a year. Side-by-side comparison.
- [Compatibility](https://circadiaos.com/compatibility/): Which smart thermostats and wearables work with CircadiaOS. Thermostats: ecobee, Honeywell Home, Google Nest, Sensi and 15+ more via HomeKit and SmartThings. Wearables: Oura Ring, Whoop, Apple Watch, Garmin, Fitbit.
- [Oura Ring + thermostat](https://circadiaos.com/connect-oura-to-your-thermostat/): Oura Ring measures your sleep but cannot act on it. CircadiaOS connects Oura Ring to your smart thermostat (ecobee, Honeywell Home, Google Nest, Sensi, and 15+ more) and runs a four-phase overnight temperature schedule that learns from your Oura sleep data. Three steps, about five minutes.
- [Contact](https://circadiaos.com/contact/): Get in touch with the CircadiaOS team for support, compatibility questions, press or partnerships. Email support@circadiaos.com or use the form.
- [Eight Sleep alternative](https://circadiaos.com/eight-sleep-alternative/): Looking for a cheaper Eight Sleep alternative? CircadiaOS gives you automatic overnight temperature control using your existing smart thermostat and wearable. $0 hardware, $99.99 a year, no new mattress. A fair side-by-side with the Pod 4.
- [FAQ](https://circadiaos.com/faq/): Answers to common questions about CircadiaOS: whether you need a smart thermostat or wearable, how the four-phase schedule works, why it is not real-time, how long calibration takes, apartments, overrides, pricing and safety.
- [For hot sleepers](https://circadiaos.com/for-hot-sleepers/): If you overheat early, kick the covers off and wake up cold by dawn, the problem is a thermostat holding one number. CircadiaOS cools your bedroom as you fall asleep and eases off before morning, using the thermostat and wearable you already own.
- [Guides](https://circadiaos.com/guides/): Plain-language guides on bedroom temperature and sleep: the best temperature for sleep, how to sleep cooler, Eight Sleep and Chilipad alternatives, connecting an Oura Ring to a thermostat, and advice for hot sleepers.
- [How to sleep cooler](https://circadiaos.com/how-to-sleep-cooler/): Nine practical ways to sleep cooler tonight: breathable bedding, a 65°F bedtime setting, airflow, a warm shower, lighter layers, cooling pulse points and more. Plus the fix most people miss: a bedroom temperature that changes overnight instead of holding one number.
- [Home](https://circadiaos.com/): CircadiaOS is an iPhone app that runs the smart thermostat you already own overnight: cooler as you fall asleep, warmer before you wake, and adjusted one change at a time from your wearable's sleep data. Works with Nest, ecobee, Honeywell Home, Sensi, and 15+ more via HomeKit and SmartThings. Nothing to buy.
- [Method](https://circadiaos.com/method/): The CircadiaOS method explained: a four-phase overnight thermostat schedule (pre-sleep, early night, late night, pre-wake), a 14-night calibration, and one-variable-at-a-time personalization held for 7 to 14 nights and judged against your own baseline.
- [Pricing](https://circadiaos.com/pricing/): CircadiaOS has two plans. Free: a starting temperature schedule, optional wearable sync and nightly sleep data. Premium: automatic thermostat control with 14-night calibration and personalization from your wearable, $12.99/month or $99.99/year, with a free trial. Cancel anytime.
- [Privacy policy](https://circadiaos.com/privacy/): How CircadiaOS LLC collects, uses, stores and protects your account, sleep, biometric and thermostat data. We do not sell your data and never share sleep data with advertisers.
- [Terms of service](https://circadiaos.com/terms/): Terms of service for the CircadiaOS app, including how the service works, compatible devices, subscription terms, medical disclaimer and safety warnings.

## Optional

- [Full text of every page](https://circadiaos.com/llms-full.txt)