Start with a pair of fairly ordinary shoes. Add to the insole, a layer of metal foil.

Now, build a magnetic induction heater, that's designed to be stood on.

When your feet are cold, step on the heater, and a pressure switch activates it.

Induction transfers electrical energy into the metal foil, where it is converted to heat by resistance.

Little electricity is wasted heating the heater -- most of it is transferred into the foil.
-- goldbb, Oct 18 2009

If it was fully built into the shoe, you'd have wires attached to your shoes. You'd have to unplug the wires from your shoes to walk any distance from the outlet.

With my idea, the wires are only attached to the magnetic induction heater, which sits on the floor, and isn't mechanically connected to the shoes. When you want to go somewhere, just go. The piece of metal foil in the insole can be left in the shoe indefinitely, without being damaged by you walking, and without harming your feet.
-- goldbb, Oct 22 2009


I've actually seen this for ski boots.
-- DrWorm, Oct 22 2009



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