Need some help sticking it out on the hard, frigid bleachers of outdoor sporting events? Lava Buns Heated Seat cushions feature an advanced MICROCORE interior that, once activated, holds heat and radiates it slowly to keep you warm and cheering in overtime! MICROCORE is a family of unique patented formulations developed by Vesture Corporation that can be made hot or cold depending on how the formula is produced and which product it is used in. MICROCORE seat cushion heating elements are activated by a microwave. Once the product is heated or chilled, it can maintain a heated or cooled temperature for hours. MICROCORE technology provides the solutions you need to keep anything hot or cold for long periods of time. All Lava Buns Seat Cushions include a manufacturer's 1 year warranty.