In this project, we were assigned to make a hand warmer (or cooler) to sell at San Marin Sports games. My group decided that we wanted to make a hand warmer to be available for the winter sport fans. We had to use water and any type of salt to be able to raise the water's temperature by 20 degrees celsius. It was a very fun project to be able to brainstorm ideas on how to keep the salt separated from the water until we wanted them to mix. Immediately, we came up with a water balloon. This idea seemed perfect to us because it kept the water and salt from not touching but we could easily pop the water balloon and have them mix. We were worried that the water balloon could pop in storage so we didn't fill it up all the way so it was harder to pop, but still easy enough to purposely break it. Please take a look at my presentation here to see more details!