Matrix Industries says its PowerWatch, a cutting-edge new wearable, is the first smartwatch powered by body heat. The watch uses thermoelectric technology to harness the electrical power naturally produced by the human body, converting it to an energy source that can keep the battery continuously charged, no wires or cables required.

As your body produces more energy — during a workout, for example — it provides the watch with more power, which can be tracked with a gauge on its face.

[youtube https://www.youtube.com/watch?v=q-fVyZSZxIw]

In addition to electricity, the PowerWatch measures calories burned, activity level and sleep. These numbers can be tracked through an accompanying mobile app.

The gadget was first funded through Indiegogo in January, and will start shipping out to customers this month. Models range in price from $169 to $249.