Self-heating Can

A self-heating can is an enhancement of the common food can. Self-heating cans have dual chambers, one surrounding the other.

In one version, the inner chamber holds the food or drink, and the outer chamber houses chemicals that undergo an exothermic reaction when combined. When the user wants to heat the contents of the can, a ring on the can is pulled to break the barrier separating the chemicals in the outer chamber. In another type, the chemicals are in the inner chamber and the beverage surrounds it in the outer chamber. To heat the contents of the can, the user pushes on the bottom of the can to break the barrier separating the water from the chemicals. This design has the advantages of being more efficient (less heat is lost to the surrounding air) as well as reducing excessive heating of the product's exterior, causing possible discomfort to the user. In either case, after the heat from the reaction has been absorbed by the food, the user can enjoy a hot meal or drink.

Self-heating cans offer benefits to campers and people without access to a microwave oven, stove or camp-fire, but the technology is not yet common. This is because self-heating cans are considerably more expensive than the conventional type, they have problems with uneven heating of their contents, and the heater takes up considerable package space.