Meet Lenz Smart Heated Socks: a product that helps you keep your feet warm during the winter season. It has 3 heat settings and lets you control it from your smartphone. These socks can keep your feet warm for up to 14 hours. They are Lithium powered and manufactured using 49% Polyester/29% polyamid/10% polyprpylen/ 7%merino/ 5% elasthan. Not cheap though.