The Alpenheat Lithium bootheater provides 3 positions of warming with anatomically shaped heating elements. The heated insole has very good isolating attributes as well as excellent damp absorbing characterics to create an optimal shoe climate. Compact re-chargeable battery pack with control electronics clips securely into mounting clip that can easily be attached to shoes, boots and belts. By means of a push-button switch, one of the two permanent heat settings, as well as the boost can be selected. Boost gives intensive heat for 6 minutes and the automatically switches back to the previously selected heat level. Easy to read LEDs indicate the current heat level.