It's no secret that our bodies give off heat, but many people don't realize that this heat can be converted into energy. The Matrix PowerWatch is doing just that; using thermoelectric technology, they created a watch that converts your body heat into energy to power their watch. Not only is the watch powered by body heat, but it also can tell you how much heat is being emitted and how many calories you're burning. During exercise, the watch harnesses more energy. The watch is also packed with a bunch of features you would expect in a smart-watch. Check out the video below to learn more about this impressive device.