Our Heat Liner + provides an additional warming layer and highly increases the hygiene of using a sleeping bag. Manufactured from an ultra-thin Toray Airtastic™ fabric, filled with Climashield insulation, allowing it to add another 7°C to a bag's rating. Heat Liner + is equipped with a zip and a hood, so it can be spread evenly and used as a cover while travelling or sleeping in a mountain hostel. This is a great solution both for wandering in the mountains and during ultra-marathons, where reliability and low equipment weight are key.