Thermorette

Thermorette is a brand of reusable hand warmers. These products are designed to provide a portable and sustainable source of heat, typically for use in cold weather. The core technology of most Thermorette products involves a supersaturated solution of sodium acetate. When the small metal disc within the hand warmer is "clicked" or bent, it initiates a crystallization process. This crystallization releases stored latent heat, causing the liquid solution to solidify and become warm to the touch.

Once activated, the Thermorette hand warmer can maintain a temperature typically between 40 and 50 degrees Celsius for a period of time, often ranging from 30 minutes to a couple of hours depending on the specific product and external conditions. To reactivate a used Thermorette, it needs to be boiled in water. This process dissolves the solidified sodium acetate crystals back into a liquid solution, resetting the hand warmer for its next use. The exact boiling time and method can vary slightly by product. Thermorette products are often marketed as an environmentally friendly alternative to disposable chemical hand warmers.