Abstract: Footwear such as a shoe or boot has an upper, an outsole and an insole. The insole comprises a layer of thermoplastic material and a heater member. The heater member is capable of generating heat by being energized by electrical energy and is capable upon being energized of effectively heating and softening the thermoplastic material so that the insole may be conformed to the shape of the underside of a foot of a person, in order to provide a custom-fitting footbed and custom-fitting footwear. The heater member preferably includes an etched foil heating element which heats by electrical resistance.