Here’s a twist on the classic chemical hand warmers you can buy for you to research and improve.
If you’ve been outdoors when it’s really cold, there’s a good chance you’ve either used these yourself or wished you had. You can experience a variation on the science found inside a commercial warmer with some pretty basic materials. You’ll discover how an everyday chemical reaction like rusting is used to keep your digits toasty. This experimental version of the hand warmer is offered as a test idea and not as a definitive solution. You’re encouraged to share your science fair results online.
Source: Homemade Hand Warmer | Science Experiments | Steve Spangler Science