- Heat Stress Index (HSI): Quantifies in real time the effort the body makes to cool itself, calculated based on core and skin temperature. The greater the effort, the greater the negative impact on performance
- Heat Zones: The HSI index is divided into 4 zones. Zone 3 is dedicated to heat training, as it triggers the physiological adaptations needed to improve performance. Time in each zone is recorded by the CORE app
- Heat Training Load: A daily score (from 0 to 10) based on time spent in Zone 3. For optimal results, 2-3 sessions per week of 45-60 minutes each in this zone are recommended
- Heat Adaptation Score: Scientifically measures (from 0 to 100%) how much the body has adapted to heat. To increase this score, it is necessary to maintain a high heat training load for several consecutive days
- Core and Skin Temperature: These are the two basic parameters detected to calculate all the previous metrics.

Specifications:
Compact dimensions: 41.9 x 29.4 x 7.1 mm (without clip) | 45.1 x 32.6 x 9.6 mm (with clip)
Manufacturer weight: 8.6 g (without clip)  |  11.4 g (with clip)
Battery: 6 days; up to 30 days with standby mode activated
Power: USB-C magnetic adapter cable (included)
Connectivity: Bluetooth Low Energy (BLE), ANT+ (2.4 GHz band)
Water resistance: up to 1.5 m (IPX7 rating)
Accuracy supported by scientific research: mean difference range from -0.01 °C to +0.23 °C