MAKE: Blog's Phillip Toronne reverse engineered a Wolfgang Punk self-heating can of coffee. (Previous post about the product here.) The self-heating container is manufactured by a company called OnTech. From Phil's post:
Here's the inner heating element, I sawed off the outside to reveal the inner chamber.
…An exothermic reaction (gives heat off) with water and calcium oxide. You can easily remove the liquid and use it for something else. I'm not sure what, but I think there are some uses for this. It's constructed like a tank, so I bet military and outdoors people might be using these.
One of the best uses might be to remove all the materials (before they're heated/water added) and show how chemical reactions can be used for something tangible for students. You could also likely do some neat things with the materials for experiments that require a small amount of heat.
