Reflecting body heat with no heat. No electric warm mat. Energy saving protection. No harsh winters or heated in warm. At night, cold and if you get. Heating your electricity bill but you should be. Heating Equipment and earbuds are getting too. 底冷e and wish.... Such as for those who may have recommended. Aluminum sheet to be filled by reflecting heat resistant thermal from severe cold and warm. Machine wash washing OK. Always clean and comfortable to use. pokkapoka. Warmth to Your Feet In The Morning until night.