Using the Reactor Extreme sleeping bag liner is a breeze. Just slip it into your sleeping bag before you go to sleep. It will enhance the warmth of your sleeping bag right away. When you're at the camp and need a bit of fresh air, you can loosen the drawcord on the footbox for better ventilation. If you want to move around the camp without taking it off, you're good to go! As for maintenance, it's recommended to follow the washing instructions on the label. Usually, a gentle machine wash in cold water is sufficient. Avoid using harsh detergents or bleach as they may damage the special ceramic pigments in the fabric. Also, let it air - dry to keep its shape and performance intact.