Developed using GreenTEG’s advanced thermal sensing technology, CORE 2 helps athletes measure and manage thermal load in real time. It is trusted by elite performers and coaches worldwide, offering medically accurate data to support heat training, pacing, and acclimatization strategies.

Compared to its predecessor, CORE 2 is 48% smaller and 30% lighter, delivering improved wearability without sacrificing performance. Its compact form factor and modular clip design allow for flexible placement — whether worn with a chest strap, clipped to a sports bra, or directly on the skin. The LED indicator keeps users informed on battery life, device status, and charging progress, while its discreet build makes it easy to forget it's even there.

When paired with the CORE Mobile App, users gain access to deep performance metrics and training guidance. The system offers real-time thermal data, historical trends, and heat adaptation support — essential for those preparing for warm-weather events or aiming to improve physiological markers like VO2 max and lactate threshold.

With backing from scientific research and usage by Olympic-level athletes such as Kristian Blummenfelt, CORE 2 has become the gold standard for performance-driven thermal monitoring.

Whether you're training indoors, competing in a hot climate, or building long-term endurance, CORE 2 gives you the ability to track, adapt, and train smarter.

Its cutting-edge tech helps you stay ahead of heat stress, prevent performance dips, and fine-tune your approach to heat acclimation and recovery.

Seamlessly connects with COROS watches to display live core body temperature data during training and racing

CORE 2 uses GreenTEG’s proprietary thermal energy transfer technology to calculate core body temperature through heat flux and skin temperature measurements.

By applying advanced algorithms, it delivers medically accurate readings — no skin patches or ingestible pills needed.

It constantly monitors your temperature during activity, providing real-time data that helps you manage heat stress and adapt your effort.

When synced with the CORE Mobile App and a heart rate monitor, CORE 2 becomes a powerful training tool.

Athletes can track how their core temperature evolves throughout a session, identify heat-related fatigue early, and implement data-informed strategies like cooling breaks or pacing adjustments.

Over time, this builds stronger heat tolerance and enhances endurance performance — especially in tough environments.