Say goodbye to one-use disposable heaters. Our Reusable Hand Warmer is a temporary warming tool for whenever you need an extra heat source. Whether at home or when you're out in the elements, this Reusable Hand Warmer delivers time and again! 1 – Bring pot of water to a rolling boil. Lower heat down to a simmer 2 – Place hand warmer in the water 3 – Keep hand warmer in water until crystals completely dissolve and liquid turns clear (~ 15 mins) 4 – Carefully remove hand warmer and allow to cool.