As for shoes, the aluminum bottom insulates the feet from cold, even extreme cold. On the foot side, the upper combines polyethylene foam for comfort and a wool/fleece and polyester blend for warmth...Shoe insoles to keep feet warm:2 pcs,The special design of these slippers, thin and light, makes them a perfect companion to wear in your shoes all winter long.Size 44-45, 1 insulating aluminum side / 1 extra warm polar side