Feet are one of the first parts to suffer from the cold while cycling. They are a long way down the blood distribution system. They are whizzing around in the breeze, making a really thin boundary layer of cold air sucking out heat. Wearing extra layers of socks usually restricts blood flow to the feet, making matters worse.

At temperatures over about 30 degrees F a pair of lined booties over summer bike shoes may work. That cutout for Look or SPD style clips lets in considerable draft. If you have an oversized pair of shoes, you\'re in luck.  You have room for an extra pair of wool or poly socks (no cotton!), and a chemical toe warmer. That may get you to about 20 degrees F.The chemical warmer(instant toe heat pack) is a fine secret weapon, it will last for hours. For most folks, booties over summer shoes just don\'t work at temperatures much below freezing.

One step up from the booties is to kludge something from any well insulated boot, using oversize mountain bike cages on a conventional clip pedal. The treads will drag on the pedal, but the feet will be warm.