llms.txt
# 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, on Premium, changes one setpoint at a time and keeps only the changes your own sleep data supports. 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 and 20+ more thermostat brands (some through Apple Home or a Samsung SmartThings hub).
- 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, 14-day free trial): 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.
- You set your own temperature floor and ceiling in the app. CircadiaOS stays within the range you choose and never goes below 63°F.
- Each change is a step of about 2°F on one phase, in a fixed order (pre-sleep, early night, late night, pre-wake), held 7–14 nights depending on the wearable, then kept or reverted.
- 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.
- [Apple Watch sleep temperature](https://circadiaos.com/apple-watch-sleep-temperature/): Apple Watch Series 8 and later, Apple Watch SE 3 and every Apple Watch Ultra measure wrist temperature while you sleep and show it as a change from your own baseline. It is not a thermometer for fever, and it is sensitive to your room and bedding. Here is how it works, which models have it, and how to use it to check your bedroom temperature.
- [Baby vs adult room temperature](https://circadiaos.com/baby-vs-adult-sleep-temperature/): For adults, common guidance is a cool room, roughly 60–67°F. For babies, the priority is avoiding overheating: the American Academy of Pediatrics gives no single number but advises against overbundling, and the UK's Lullaby Trust suggests 16–20°C (about 61–68°F). Here is how the two fit together when you share a room.
- [Best smart thermostat for sleep](https://circadiaos.com/best-smart-thermostat-for-sleep/): For sleep, the features that matter are a sensor in the bedroom, enough overnight schedule changes to follow a curve, and an app you will actually use. Here is how ecobee, Google Nest, Honeywell Home T9, Mysa and Sensi compare on those points, and why the thermostat you already own is usually good enough.
- [Best temperature for sleep](https://circadiaos.com/best-temperature-for-sleep/): Most sleep guidance 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.
- [Compare](https://circadiaos.com/compare/): Compare the real cost of CircadiaOS, Eight Sleep Pod, and ChiliPad over 1–3 years. Spoiler: you probably already own everything you need.
- [Compatibility](https://circadiaos.com/compatibility/): Which smart thermostats and wearables work with CircadiaOS. Thermostats: Nest, ecobee, Honeywell Home and 20+ more brands, including Sensi, Trane and Mysa. Wearables: Oura Ring, Whoop, Apple Watch, Garmin, Fitbit.
- [Apple Watch + thermostat](https://circadiaos.com/connect-apple-watch-to-your-thermostat/): Apple Watch tracks your sleep but cannot change your thermostat. CircadiaOS connects your Apple Watch sleep data to your smart thermostat (ecobee, Nest, Honeywell Home, Sensi, and more) and runs a four-phase overnight temperature schedule that learns from your nights.
- [Garmin & Fitbit + thermostat](https://circadiaos.com/connect-garmin-fitbit-to-your-thermostat/): Garmin and Fitbit track your sleep stages and heart rate but cannot change your thermostat. CircadiaOS connects your Garmin or Fitbit sleep data to your smart thermostat and runs a four-phase overnight temperature schedule that learns from your nights.
- [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 20+ more) and runs a four-phase overnight temperature schedule that learns from your Oura sleep data. Three steps, about five minutes.
- [Whoop + thermostat](https://circadiaos.com/connect-whoop-to-your-thermostat/): Whoop measures recovery and sleep performance but cannot act on it. CircadiaOS connects your Whoop data to your smart thermostat and runs a four-phase overnight temperature schedule that learns from your recovery scores. No new hardware.
- [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.
- [Couples + thermostat](https://circadiaos.com/couples-bedroom-temperature/): One partner runs hot, the other runs cold. A flat thermostat setting all night guarantees someone loses. Learn how an overnight temperature curve can help both sleepers, and how CircadiaOS automates it.
- [ecobee sleep mode](https://circadiaos.com/ecobee-sleep-mode/): ecobee's built-in sleep comfort setting holds one temperature all night. That helps, but your body needs a curve. Here is what ecobee sleep mode actually does, how to manually build a multi-phase schedule, and how CircadiaOS automates it.
- [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 setup 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 Oura Ring, Apple Watch, or Whoop to a thermostat, wearable temperature readings, thermostat-specific setup for ecobee, Nest, Honeywell, Mysa and Sensi, summer and winter settings, night sweats, couples and hot sleepers.
- [Honeywell sleep schedule](https://circadiaos.com/honeywell-thermostat-sleep-schedule/): Honeywell Home thermostats support time-based schedules, but most people set one bedtime temperature. Learn how to build a four-phase overnight curve on your Honeywell T9, T10 Pro, or Lyric, or let CircadiaOS do it automatically.
- [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 and 20+ more thermostat brands. Nothing to buy.
- [Menopause + thermostat](https://circadiaos.com/menopause-night-sweats-thermostat/): During perimenopause and menopause, one thermostat setting can feel too warm at midnight and too cold at 4am. Here's how an overnight temperature curve works, how to set one up, and what CircadiaOS does on the thermostat you already own.
- [Menopause](https://circadiaos.com/menopause/): Waking up hot at 3am and cold by dawn? CircadiaOS runs the smart thermostat you already own through four temperatures overnight. No new bed or cooling pad. Wellness app, not a medical device.
- [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 starting period, and one-variable-at-a-time adjustments held for 7 to 14 nights and judged against your own starting point.
- [Mysa sleep schedule](https://circadiaos.com/mysa-thermostat-sleep-schedule/): Mysa thermostats control one room at a time, which makes them good for a bedroom-only sleep schedule. But baseboard, in-floor and mini-split heat respond at very different speeds, so the timing of your overnight changes matters. Here is how to set a four-phase sleep schedule on Mysa.
- [Nest sleep settings](https://circadiaos.com/nest-thermostat-sleep-settings/): Google Nest lets you set a sleep temperature, but one number all night is a compromise. Learn how Nest's sleep schedule works, how to add multiple overnight setpoints manually, and how CircadiaOS automates a four-phase curve on your Nest every night.
- [Night sweats, not menopause](https://circadiaos.com/night-sweats-not-menopause/): Night sweats happen to men and women of every age. The most common causes are a hot bedroom or heavy bedding, anxiety, alcohol, medicines and infections; less often thyroid problems, low blood sugar or, rarely, some cancers. Here is how to tell environmental sweating from true night sweats, and which symptoms mean you should see a doctor.
- [Oura temperature + thermostat](https://circadiaos.com/oura-temperature-and-thermostat/): Oura's temperature reading is your finger skin temperature compared with your own baseline, not your core temperature. A warm bedroom, a heavy duvet, alcohol, illness and your cycle can all move it. Here is how to read it and how to check whether your thermostat is part of the story.
- [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 a 14-night starting period and one-variable-at-a-time adjustments 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.
- [Quiz](https://circadiaos.com/quiz/): Answer five quick questions about your sleep and get your own overnight temperature curve for your bedroom. Takes about 60 seconds.
- [Sensi sleep schedule](https://circadiaos.com/sensi-thermostat-sleep-schedule/): Sensi smart thermostats support scheduled temperature changes, but most people set one bedtime number. Learn how to build a multi-phase overnight schedule on your Sensi thermostat, or let CircadiaOS send one automatically every night.
- [Setup](https://circadiaos.com/setup/): CircadiaOS uses the smart thermostat and wearable you already own. Here is exactly what you need, what the setup looks like step by step, and what happens on your first night.
- [Sleeping hot next to a partner](https://circadiaos.com/sleeping-hot-next-to-partner/): A sleeping adult gives off roughly as much heat as an old incandescent bulb, and a shared duvet and foam mattress trap it. That is why many people sleep hotter with a partner than alone. Here is what causes it and what helps: separate covers, the right mattress layer, airflow, and a bedroom that is coolest in the first half of the night.
- [Smart thermostat sleep schedule](https://circadiaos.com/smart-thermostat-sleep-schedule/): A single overnight temperature is wrong. Learn how to program a four-phase sleep schedule on ecobee, Nest and Honeywell thermostats, or let CircadiaOS do it automatically with the thermostat you already own.
- [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.
- [Summer vs winter sleep settings](https://circadiaos.com/thermostat-setting-for-sleep-summer-winter/): Your body wants roughly the same bedroom in July and January: about 60–67°F, coolest early in the night and a little warmer before you wake. What changes is how you get there. Here are practical overnight settings for heating and cooling season, what they cost, and the mistakes to avoid with heat pumps and humidity.
- [Whoop + a hot bedroom](https://circadiaos.com/whoop-hot-bedroom/): A warm bedroom can raise your overnight heart rate, cut into deep and REM sleep and increase wake-ups, and those are among the inputs Whoop uses for recovery and sleep performance. Here is what the research says, how to check it in your own Whoop data, and what to change.
- [Waking up at 3am](https://circadiaos.com/why-do-i-wake-up-at-3am/): Waking up at 3am or 4am every night is one of the most common sleep complaints. One underappreciated cause: your body's core temperature hits its lowest point around this time, and a room that is too cold makes the wake-up worse. Learn how an overnight temperature curve can help.
- [Why do I wake up hot?](https://circadiaos.com/why-do-i-wake-up-hot/): Waking up hot is usually about the room, the bed or what you did in the evening: a thermostat held at one number, heat-trapping bedding, a partner's body heat, alcohol or a late meal. Hormones, medicines and some medical conditions play a part too. Here is how to work out which, and when to see a doctor.
## Optional
- [Full text of every page](https://circadiaos.com/llms-full.txt)
