Hot Hands, Instant Crystals, and Super Cool Solutions

As the weather gets colder, fingers get frosty. Most chemical hand warmers are single use and take a while to warm up. But it's easy to make an instant, reusable hot pack with two simple ingredients: baking soda and vinegar. Follow the recipe below to make your own at home!

Materials:

• 1 cup white vinegar (acetic acid C₂O₂H₄)
• 5 level teaspoons of baking soda (sodium bicarbonate NaHCO₃)