Thermorettes

Thermorettes are small, portable heating devices that typically utilize a chemical reaction to generate heat. They are commonly used to provide warmth in cold environments or for therapeutic purposes. The most frequent type of thermorette contains a mixture of iron powder, activated carbon, salt, and water. When the sachet is exposed to air, the iron powder oxidizes, a process that releases heat. This exothermic reaction continues until the oxygen supply is depleted or the reactants are exhausted.

These disposable heating pads are often found in the pockets of skiers, campers, or anyone spending time outdoors in frigid weather. They can be slipped into gloves, pockets, or boots to keep extremities warm. In a medical context, thermorettes can be applied to sore muscles or joints to promote blood circulation and alleviate pain, functioning as a form of heat therapy.

The activation process is straightforward: the user typically shakes or kneads the sachet to break an inner seal and expose the contents to air, initiating the chemical reaction. The heat generated is generally mild and lasts for several hours. Once cooled, thermorettes are disposed of. Their simplicity and effectiveness have made them a popular personal heating solution.