Being cold isn’t fun. So we bring you the perfectly named Heart Hand Warmer. But unlike most hand warmers, this one you can use over and over again. And, you don’t have to pop it in the microwave to heat up.

The magic with the heart hand warmer is in the metal disc you see inside it. All you do is click the disc back and forth a few times and you’ll see the clearish gel inside become opaque. As the opaqueness spreads, so does the heat! It’s a crazy chemical reaction which we like to call AWESOME! Seriously, the pretty red gel is a supersaturated solution. Bending the disc starts an exothermic crystallization of the gel (i.e. it goes opaque and gets hot). And when it loses its warmth, all you have to do is wrap it in a towel and throw it into boiling water for about 15-20 minutes and the Heart Hand Warmer resets itself. Once it cools off from its boiling bath, it is ready to be used again. A great, fun way to keep your fingers warm this winter. Got a chilly butt? Then slip it in your back pocket. Just be careful when you sit down.

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