Most people can guess that the handwarmers we use so often, especially during the colder seasons, is warm as a result of chemical reactions. How is it, however, that with a simple shake, it awakens the chemicals to suddenly react with each other? Which chemicals are the best at giving off heat during reaction? How do they actually work? Our recent study of thermodynamics has led me to become curious about those little helpful packages of warmth. The best kind of hand warmers are ones that get up to the perfect temperature quickly. Another factor to consider when purchasing hand warmers is their effects on the environment. There are two primary types of hand warmers, the reusable hand warmer, and the disposable hand warmer. Like reusable