Say goodbye to cold feet! With extremely low-profile, hidden heat elements woven discreetly into the soles and compact battery packs that fastens seamlessly to the top of the socks’ cuffs, the Therm-ic Sock Set Heat Fusion Uni + S-Pack 1400B Socks offer customizable warmth for up to 16 hours. Controllable via Bluetooth technology and the Therm-ic Heat Control app, these heated socks will revolutionize your ski days.