--- title: HYDR8 Will Lead You To Water, But Will You Drink? description: A hobbyist built HYDR8, a wearable powered by a XIAO ESP32-C3 that monitors heart rate, blood oxygenation, skin temperature, and ambient temperature and... canonical: https://daily.dev/posts/hydr8-will-lead-you-to-water-but-will-you-drink--jvg7yatdx twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: HYDR8 Will Lead You To Water, But Will You Drink? | daily.dev og:description: A hobbyist built HYDR8, a wearable powered by a XIAO ESP32-C3 that monitors heart rate, blood oxygenation, skin temperature, and ambient temperature and... og:url: https://daily.dev/posts/hydr8-will-lead-you-to-water-but-will-you-drink--jvg7yatdx og:image: https://api.daily.dev/og/posts/JvG7yatDx.png og:image:alt: HYDR8 Will Lead You To Water, But Will You Drink? og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # HYDR8 Will Lead You To Water, But Will You Drink? **[Hackaday](https://daily.dev/sources/hackaday)** · 2 min read · 1 upvotes · 1 comments ## Summary A hobbyist built HYDR8, a wearable powered by a XIAO ESP32-C3 that monitors heart rate, blood oxygenation, skin temperature, and ambient temperature and humidity to compute a heat/hydration stress score from 0-100. Rather than generic reminders, it tells the wearer specific actions like 'drink water' or 'find shade.' The device pairs with a phone-hosted dashboard served from the ESP32 and is explicitly a prototype, not a medical device—it estimates hydration stress rather than actual hydration levels. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### What sensors does the HYDR8 wearable use to estimate hydration stress? It uses a XIAO ESP32-C3 microcontroller paired with sensors for heart rate, blood oxygenation, skin temperature, and ambient temperature and humidity. The device also learns a wearer's personal resting baseline over time and combines all these readings into a single heat and hydration stress score from 0 to 100, then displays a specific action like drinking water or finding shade. _daily.dev surfaces maker builds like this for developers exploring sensor-driven wearable projects._ ## Community discussion Top comments from developers on daily.dev. **@frazzledturtle** · 0 upvotes > Tbh I'm glad to see wearables getting out there and trying new things ## Similar posts on daily.dev - [Hiyd is a health tracker that attaches to the watch you already wear](https://daily.dev/posts/hiyd-is-a-health-tracker-that-attaches-to-the-watch-you-already-wear-l4r5xn2bf) · TechCrunch · 0 upvotes · 0 comments - [An Open Heart Rate Monitor](https://daily.dev/posts/an-open-heart-rate-monitor-lxa1d8rhe) · Hackaday · 0 upvotes · 0 comments - [You, too, can build this ESP32 e-Ink environmental monitor for temperature and humidity tracking](https://daily.dev/posts/you-too-can-build-this-esp32-e-ink-environmental-monitor-for-temperature-and-humidity-tracking-j7mfo6lu9) · XDA Developers · 1 upvotes · 0 comments - [DIY ESP32-P4 weather station & air quality monitor connects to LoRa and ESP-NOW sensors, various weather APIs](https://daily.dev/posts/diy-esp32-p4-weather-station-air-quality-monitor-connects-to-lora-and-esp-now-sensors-various-wea-fyniccq3k) · CNX Software · 0 upvotes · 0 comments - [A DIY Watch You Can Actually Wear](https://daily.dev/posts/a-diy-watch-you-can-actually-wear-fy1barpng) · Hacker News · 1 upvotes · 0 comments --- Tags: [#hardware](https://daily.dev/tags/hardware), [#iot](https://daily.dev/tags/iot) [View this post on daily.dev](https://daily.dev/posts/hydr8-will-lead-you-to-water-but-will-you-drink--jvg7yatdx) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"HYDR8 Will Lead You To Water, But Will You Drink?","url":"https://daily.dev/posts/hydr8-will-lead-you-to-water-but-will-you-drink--jvg7yatdx","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/hydr8-will-lead-you-to-water-but-will-you-drink--jvg7yatdx"},"datePublished":"2026-08-19T23:07:58.169Z","dateModified":"2026-09-14T08:06:46.625Z","description":"A hobbyist built HYDR8, a wearable powered by a XIAO ESP32-C3 that monitors heart rate, blood oxygenation, skin temperature, and ambient temperature and...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/a3b5bc77e9869b61e403afd40b3171df?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/a3b5bc77e9869b61e403afd40b3171df?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Hackaday","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Hackaday","logo":"https://media.daily.dev/image/upload/s--JhDfhy70--/f_auto,q_auto/v1767541814/logos/hackaday","url":"https://daily.dev/sources/hackaday"},"commentCount":1,"discussionUrl":"https://daily.dev/posts/hydr8-will-lead-you-to-water-but-will-you-drink--jvg7yatdx","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":1},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":1}],"keywords":"hardware,iot","timeRequired":"PT2M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Hackaday","item":"https://daily.dev/sources/hackaday"},{"@type":"ListItem","position":3,"name":"HYDR8 Will Lead You To Water, But Will You Drink?"}]} {"@context":"https://schema.org","@type":"WebPage","@id":"https://daily.dev/posts/hydr8-will-lead-you-to-water-but-will-you-drink--jvg7yatdx","comment":[{"@type":"Comment","text":"Tbh I’m glad to see wearables getting out there and trying new things","datePublished":"2026-08-23T11:23:58.588Z","url":"https://daily.dev/posts/JvG7yatDx#c-AWLYglMua","author":{"@type":"Person","name":"Avrazi","url":"https://daily.dev/frazzledturtle","image":"https://media.daily.dev/image/upload/s--0nq21E-v--/f_auto/v1790757187/avatars/avatar_yJnih5f2FyWGd45ROzjmJ?_a=BAMAMicg0"}}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/hydr8-will-lead-you-to-water-but-will-you-drink--jvg7yatdx#faq","mainEntity":[{"@type":"Question","name":"What sensors does the HYDR8 wearable use to estimate hydration stress?","acceptedAnswer":{"@type":"Answer","text":"It uses a XIAO ESP32-C3 microcontroller paired with sensors for heart rate, blood oxygenation, skin temperature, and ambient temperature and humidity. 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