Comparison

CORE Thermal Sensor vs Calibre Biometrics

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

CORE Thermal Sensor

This app continuously monitors your core body temperature and thermal strain, providing critical data for heat training and optimal race performance. It helps athletes of all levels improve their training and achieve better results.

Highlights
  • 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
Features
Read full description

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.

About

Calibre Biometrics

This app pairs with a wearable device to track and analyze key metabolic and performance metrics like VO2 Max and resting metabolic rate. It provides detailed insights into your body's energy expenditure and fat burning zones. Designed for informational and educational use, it complements professional health guidance.

Highlights
  • View biometric data
  • Record metabolic information
  • Analyze VO2 Max
  • Monitor Resting Metabolic Rate
  • Track FatMax and Calories
  • Companion to wearable tracker
Read full description

The companion app to the Calibre™ wearable breath/metabolic tracker allows you to view, record and analyze the rich biometric information obtained by the Calibre device. A device with groundbreaking accuracy for measuring and monitoring VO2 Max, Resting Metabolic Rate, FatMax, Calories and more with a lightweight, portable device that is simple and easy to use. Disclaimer Calibre is intended for informational and educational purposes only and should not be used as a substitute for professional medical advice or devices.

Screenshots

CORE Thermal Sensor4 screens
Calibre Biometrics4 screens

Verdict

The call

The clearest difference is rating: Calibre Biometrics at 4.5 against CORE Thermal Sensor's 2.5. Calibre Biometrics also leads on review sentiment (50% vs 19%) and update cadence (every 4 weeks vs every 2 months). CORE Thermal Sensor's advantage is in-app purchases (none vs 1) and ratings volume (35 vs 2). On price, ads, monetization model and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Calibre Biometrics sells 1 in-app purchase, starting at $7.99 per month. CORE Thermal Sensor asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Calibre Biometrics holds the better App Store score, 4.5 against 2.5. That said, the two scores are not equally well evidenced: CORE Thermal Sensor has 35 ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 19% of CORE Thermal Sensor's written reviews are positive against 50% of Calibre Biometrics's.

UpkeepUpdate frequency

CORE Thermal Sensor ships an update every 2 months, Calibre Biometrics every 4 weeks. The most recent releases landed on October 23, 2026 and October 24, 2026 respectively.

Scorecard5 real differences · 5 level
CORE Thermal Sensor versus Calibre Biometrics: the parameters behind the verdict, then further details
ParameterCORE Thermal SensorCalibre Biometrics
PriceFreeFree
Rating2.5 (35 ratings)4.5 (2 ratings) — better
Positive reviews18.8% of reviews50.0% of reviews — better
Number of ratings35 — better2
Update frequencyEvery 2 monthsEvery 4 weeks — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFreeFree
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.1 — better15.4
Further details — not scored
Size55 MB116 MB
Age rating4+4+
Developergreenteg AGBreathTaking Tech LLC

Customer experience

CORE Thermal Sensor

All ratings35 ratings
Positive22.9%
Neutral20.0%
Negative57.1%
Written reviews48 reviews
Positive18.8%
Neutral25.0%
Negative56.3%

Calibre Biometrics

Written reviews2 reviews
Positive50.0%
Neutral0.0%
Negative50.0%

In-app purchases

None

CORE Thermal Sensor

No in-app purchases

1 purchases

Calibre Biometrics

Subscriptions1
  • Calibre Premium$7.991 Month

Questions

Is CORE Thermal Sensor free?
CORE Thermal Sensor is free to download, with no in-app purchases.
Is Calibre Biometrics free?
Calibre Biometrics is free to download, with in-app purchases available.
Which has better reviews, CORE Thermal Sensor or Calibre Biometrics?
Calibre Biometrics is rated higher. CORE Thermal Sensor averages 2.5 out of 5 from 35 ratings, while Calibre Biometrics averages 4.5 from 2 ratings.
Do CORE Thermal Sensor or Calibre Biometrics have ads?
Neither CORE Thermal Sensor nor Calibre Biometrics shows ads.
Which is updated more often, CORE Thermal Sensor or Calibre Biometrics?
CORE Thermal Sensor ships an update every 2 months, and Calibre Biometrics every 4 weeks. Most recently, CORE Thermal Sensor was updated on October 23, 2026 and Calibre Biometrics on October 24, 2026.

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