Ever feel like you’re about to get frostbite out in the cold? Small heating pads in your pockets could help you cope.
Get through the icy cold of the winter with tiny heating pads that you could hold, stuff your pockets with or simply just sit on. Heating pads are small bags filled with hot material that stay hot for a while, providing you with warmth while outside. These are not new, but people have been reluctant to use them because they don’t believe how efficient they are. We tried them, and they are awesome.
Our team was at first skeptik over both how well they heated and how many times they can be reused. According to the package manual, they can be reused up to 1000 times, so we put them to the test.
The small transparent red pads contain a see through liquid and a small metallic disk. The instructions said press the disk to start the heating process, and it actually did. Within second the whole pad solidified and generated immense heat, enough to warm you up no matter how you use them. So we did some research to find out how they work.
The reusable hand warmer pads are usually filled with a supersaturated solution of sodium acetate, or 3H2O CH3COONa, in water. When you flex the small disk, crystallization is triggered by the release of very tiny adhered crystals of sodium acetate into the bag, mixing with the solution and act as nucleation site where the sodium acetate is turned into hydrated salt. Because of the liquids supersaturation, the solution crystallizes very quickly, releasing the energy of crystal lattice.
Well now that the bags were hot and solid, we didn’t believe they could ever be used again. But we were wrong.
After about an hour, the bags cooled down, and we were ready to test their reusability. As per the instructions, all we had to do was place them boiling water for 10–15 minutes. The boiling water dissolves the sodium acetate trihydrate inside the bag to recreate the supersaturated solution. And once it went back to room temperature, it was ready to be triggered again.
Keep in mind that the heating pads are very helpful if you’re not wearing gloves or if you want to warm up after holding snow or something really cold. They typically stay hot from anywhere between 20 minutes to 2 hours, depending on their brand and quality.