# CORE Thermal Sensor — Temperature Monitoring System > Continuous core body temperature and thermal strain monitoring for athletes. (iPhone/iPad app by greenteg AG.) - Source: https://appshunter.io/ios/app/core-thermal-sensor/id1521866309 (this page in markdown: same URL + `.md`) - Developer: [greenteg AG](https://appshunter.io/developer/1510577388) - Category: Health & Fitness, Sports - Price: Free - Rating: 2.52/5 from 33 App Store ratings · 30 written reviews indexed - Age rating: 4+ - Requires: iOS 15.1 · 55 MB - Languages: Dutch, English, French, German, Italian, Japanese, Spanish, Chinese - Released: 2020-09-24 - Data updated: 2026-07-29 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/core-thermal-sensor/id1521866309/reviews.md ## What is CORE Thermal Sensor? The CORE Thermal Sensor accurately measures your core body temperature and thermal strain on your body – continuously and non-invasively. Thermal data and insights are critical for facilitating safe and effective heat training and for performing optimally on race day. Designed for athletes at all levels, CORE will help to improve your training and performance in your personal adventures or races. IMPORTANT: The CORE app is designed to work with the CORE device which you can order at www.corebodytemp.com Here's how it works: • Set up your CORE sensor: connect your heart rate monitor and sports devices for optimal sensor use. • Measure your thermal vitals during training: mount the newly designed clip on your heart rate strap and snap in the CORE sensor. Shake the sensor to wake it up, wear it and track your thermal data. • Core body temperature: the interior temperature deep in your body, including organs and other tissues. A critical measure during sports, it can reach up to 40°C (104°F) during vigorous activity in hot environments. Be aware that hotter is not better – cooler is faster. • Heat Strain Index: A combination of your core body temperature and skin temperature representing the thermal strain on your body. The real-time feedback on how hard your body is working to stay cool, delivering a value from 0 (no heat strain) to around 10 (extremely high heat strain). • Heat Zones: Your Heat Strain Index divided into easy-to-use zones. Heat Zone 3 will likely lead to a performance loss, BUT it is the needed stimuli to create adaptations in your body. During heat training, strive for time in heat zone 3. During racing, stay cool and prevent a performance loss by staying in heat zone 1 or 2. • Heat Training Load: a cumulative daily metric of the heat strain on your body. A daily value of 10 out of 10 indicates ideal contribution to heat adaptations. More is not always better! • Heat Adaptation Score: Track your heat adaptations over time with effective heat training. Get a heat champion to perform best in the heat. Long-term heat training will most likely lead to improvements also in cool conditions. • Add your passive heat training: Supplementing your active heat training or general training with passive heat exposure in a sauna or hot bath. You can track your sessions in the app manually, contributing to your heat adaptation score. NOTE: do NOT take your CORE sensor into the sauna or hot environments. What else you can do in the CORE app: • Dig into the details: See a breakdown of your thermal data, and even see trends across days, weeks and months. • Share your CORE metrics with your friends through the social sharing feature, earning more kudos and likes • Connect your connectivity accounts (e.g. Garmin) to directly synchronize your data after the training. • Update your sensor to the latest firmware ensuring having the best sensor functionality. Note: CORE provides products and services designed for general fitness and training purposes. For accurate measurement readings during sports, a connection to a heart rate monitor is necessary. CORE products and services are not medical devices, not intended to treat or diagnose any disease, and should not be used as a substitute for professional medical advice, diagnosis or treatment. All content available through CORE products and services is for general informational purposes only. ## Key features - Continuous core body temperature monitoring - Real-time Heat Strain Index - Heat Zones for training and racing - Heat Training Load and Adaptation Score - Passive heat training tracking - Data trends and historical analysis - Connectivity with sports devices ## Recent user reviews (10 of 30) All indexed reviews: https://appshunter.io/ios/app/core-thermal-sensor/id1521866309/reviews.md ### 1/5 — Great potential but….complex connectivity zero support. *2026-06-25, version 2.5.3* Love the intentions but the app is cumbersome the connectivity very fragile and in consistent. Analysis shows data that is not on the dash board. Paring with HRMs also inconsistent and unreliable if the monitor is in use by any other app/ device. My big bugbear is the battery retention, use one and leave it with 60% return a week later and the battery is dead and the fact it’s a unique adaptor is also a pain.i like the direction it’s sending me it’s just the journey is not as enjoyable and easy as it should be data captured on a Wahoo missed by this app, as such no value in wearing. Garbage is my last eat opinion . ### 3/5 — Potential not realized *2026-06-01, version 2.5.3* I’ve been using the core 2 for over a year. This app is half baked. Connection to the core 2 sensor can be very frustrating. There is significant lag with readings. I often use the app to track my heat strain in real time, but the app doesn’t reliably tabulate either time in zone. I’ve been riding for an hour as I write this and all the zones on the histogram say zero. The daily heat training bar also says zero. So you can’t use a daily heat training load as a daily end point for your training. Also, when logging passive heat training, it would be nice if it calculated how much time you needed to spend doing each activity to achieve a particular daily heat training load. E.g. based on the ride I’m doing now, it would be nice if the app told me I had to do 20 minutes of sauna to achieve the daily heat load of 10. ### 1/5 — Buggy and hard to get hold of support *2025-12-28, version 2.5.1* Won’t connect reliably with tp link Bluetooth adapter and disconnects from Zwift if companion app is in background unlike other Bluetooth sensors. ### 1/5 — Don’t waste your time *2025-10-22, version 2.5.0* Attempted to purchase one of these to track body temp while training. On 2 attempts core failed to ship the device in a timely manner or at all. Waited weeks on both attempts to get the device only to hear excuses like it was shipped back “we’re not sure why”. For the money they’re asking for this, it’s not worth it. ### 1/5 — Cannot get past setup screen *2025-09-27, version 2.4.0* IOS 26 Cannot even get past the initial setup. Just get Failed to Save Preferences no matter what I choose. ### 1/5 — App can not to open up *2025-07-16, version 2.4.0* The app can not to open up normally. ### 1/5 — They’re good at accepting your payment. So far, nothing else. *2025-07-10* I’ve placed my order four days ago. It hadn’t shipped yet. They haven’t replied to any of my messages. So far, this smells like pure techbro hype: they over promise and don’t deliver. But maybe the product will be fantastic. Assuming it gets to me… ### 3/5 — Could be great! *2025-06-03, version 2.4.0* Useful training tool let down by a slow app. The live metrics seem to work but the time in zone, heat training load and heat adaption score can be very slow to update for some reason. Surely this is an easy fix! ### 3/5 — New sensort *2025-05-29, version 2.4.0* I just changed to the new sensor. Everything was fine with the old one but now the data from todays ride/effort is not transfered to my « overall heat score ». It just stays at 0. It feels like lates UI update about a month or two ago doesn’t work well ### 3/5 — Added passive, doesnt work *2025-04-24, version 2.4.0* The adding of passive heat is great but setting the date doesn’t work… ## Frequently asked questions about CORE Thermal Sensor ### What does the CORE Thermal Sensor app do? The CORE Thermal Sensor app continuously measures your core body temperature and thermal strain. This data is crucial for optimizing heat training, improving performance during races, and understanding how your body responds to heat. ### What are the key features of the CORE app? Key features include continuous core body temperature monitoring, a real-time Heat Strain Index, Heat Zones to guide training and racing, Heat Training Load and Adaptation Scores, and the ability to track passive heat training. It also offers data trend analysis and connectivity with other sports devices. ### Is the CORE Thermal Sensor app free to use? Based on the provided information, the CORE app is free to use. However, it requires the CORE device, which must be ordered separately from their website. ### What devices is the CORE app compatible with? The CORE app is designed to work with the CORE device. It also allows you to connect your heart rate monitor and other sports devices, such as Garmin, for optimal sensor use and data synchronization. ### How can the CORE app help with heat training? The app provides insights into your core body temperature and thermal strain, allowing you to strategically train in Heat Zone 3 to build adaptations. It also tracks your Heat Training Load and Heat Adaptation Score to ensure you are effectively preparing for heat exposure and performing optimally. ## Version history (last 5 releases) ### 2.5.4 — 2026-06-25 • Improved editing capabilities for passive Heat Training Load • Other small bugfixes and improvements. ### 2.5.3 — 2026-04-13 • Added option to delete passive Heat Training Load entries. • Other small bugfixes and improvements. ### 2.5.2 — 2026-02-04 • Bug fixes and improvements ### 2.5.1 — 2025-12-22 • Added a button for convenient change of the app language • Other small bugfixes and improvements ### 2.5.0 — 2025-10-02 • Added new Coach Mode to supervise your athletes. • Data from all your CORE sensors is now merged in the various charts. • Other small bugfixes and improvements. ## Apps similar to CORE Thermal Sensor | App | Rating | Price | Category | | --- | --- | --- | --- | | [Body Temperature - HealthTrack](https://appshunter.io/ios/app/body-temperature-healthtrack/id6471901980) | 4.5 (76) | Free | Health & Fitness | | [Natural Cycles Fertility App](https://appshunter.io/ios/app/natural-cycles-fertility-app/id765535549) | 4.8 (29,593) | Free | Health & Fitness | | [Thermo - 헬스케어 또 체온계 다이어리](https://appshunter.io/ios/app/thermo/id1046767441) | 3.6 (97) | Free | Health & Fitness | | [Body Temperature Tracking App](https://appshunter.io/ios/app/body-temperature-tracking-app/id1117328173) | 3.5 (18) | Free | Health & Fitness | | [Body Temperature Tracer](https://appshunter.io/ios/app/body-temperature-tracer/id1125601818) | 2.2 (33) | Free | Health & Fitness | | [Fever thermometer: temperature](https://appshunter.io/ios/app/fever-thermometer-temperature/id6657979898) | 4.8 (157) | Free | Health & Fitness | ## More apps by greenteg AG - [calera - core body temp](https://appshunter.io/ios/app/calera-core-body-temp/id1631750185) All apps by greenteg AG: https://appshunter.io/developer/1510577388 ## Related topics [core](https://appshunter.io/ios/topics/core) --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-07-29.*