Cycling shoes are pretty ventilated. I guess the foil would block some cold air. Foil may reflect some heat, like those mylar survival blankets. I would think foil would be uncomfortable.
Back when toe clips were in wide use, before clip less, they used to sell cover that would attach to the straps and cover the toes same principal.
I have some old shoe covers that had a broken zipper. I cut the backs off and just use the toes. I cut them off past the cleats so they stay on.
Bill
Last edited by LongT; 10-23-17 at 08:32 AM.