Now that winter is nearly upon us here in Seattle, the overnight lows have been hitting well below freezing. The worst part is while walking, or waiting for the bus, I could feel the ground sucking all my body heat through the soles of my feet.
I started shopping for thermal insoles (hard to find, apparently) and came across a few patent and trademark disputes that discussed the composition of these thermal insoles. They consist of roughly 3 layers, a bottom layer (presumably made of rubber) for keeping the insoles in place, a middle layer that acts as a heat shield, and a top layer that acts as an insulator and padding for your feet.
Here's the secret: The "heat shield" layer is basically a sheet of aluminum foil.
Naturally, after reading that, I decided i could make it myself. I picked up some new Memory Foam™ insoles (for insulation) and stuck a sheet of aluminum foil in my shoes before sticking the new insoles.
Does it work? Let me just say that before I did this, the sidewalks were covered in ice, and after making my tin foil shoes, there's water everywhere. Coincidence?