Warm feet in the sleeping bag. Cold feet are out, because if you freeze, you feel uneasy. The new "Feater" - "The Feet Heater" from Grüezi bag can help here. It fits into every sleeping bag, thereby increasing the insulation value and the highlight, you can even heat it up with a standard power bank. A great gadget not only in the sleeping bag, but also on the couch at home. to the sports market