The Mission Flux Hand Warmer offers instant heat during the coldest of conditions. As soon as the platelet is clicked the gel crystallises and steadily releases heat. To reuse simply place the hand warmer into boiling water until the crystals dissolve. Mission Flux Luxury Reusable Hand Warmer. To use this product – simply press the metal platelet inside the product. To Reuse: Place in boiling water for 5-10 minutes. Stays warm for up to 30 minutes.