The First Ascent Thermolite Sleeping Bag Liner is specially designed for extreme environments as it adds up to 15°C of warmth to a sleeping bag.
This mummy shaped sleeping bag liner incorporates a lining for your sleeping bag’s cowl helping to keep the whole of your bag clean and warm.
The First Ascent Thermolite Sleeping Bag Liner adds up to 15°C warmth to the temperature rating on your sleeping bag. This is thanks to the permanent insulation qualities of the Thermolite fabric by DuPont which will keep you warm whilst remaining breathable. This liner is most effective when combined with sleeping bags with a comfort rating of 0°C or less