When choosing a sleeping bag liner you have more than a few options for material. Some materials, like silk, are great because they just feel amazing to sleep against. Others, like fleece, are warm but also extremely bulky and heavy, and not very practical for most campers and backpackers. Thermal sleeping bag liners, more often referred to as thermolite sleeping bag liners, have one big thing going for them, which is a lot of warmth without a lot of weight, making them ideal for backpackers and campers looking to save on weight and bulk.
Thermal Sleeping Bag LinerWhat features you should be watching for when you are shopping for a thermal sleeping bag liner.
- Degrees Added – When buying a thermal sleeping bag liner you have to give serious thought to just how many degrees you want added to your sleeping bag. Thermal sleeping bag liners can add a surprisingly large amount of warmth, and keep in mind that there are other materials that will add warmth too, though usually not as much as thermolite.
- Shape – You want to make sure to get a sleeping bag liner that is the same shape as the sleeping bag it will be used in. A rectangular sleeping bag liner, for instance, will be too large for a mummy shaped sleeping bag.
Best Thermal Sleeping Bag LinerThere aren't too many thermal sleeping bag liners out there, but these are the best of them.
- Cocoon Thermal Liner - First, a good thermal sleeping bag liner from Cocoon, who make quite a few different liners. It's made with CoolMax fabric, a kind of polyester, which helps to wick away moisture well. It also adds quite a bit of warmth, something like 10 to 12 degrees, and weighs 15.4 ounces, or 436 grams, which is kind of heavy, relative to how much warmth you get. It's also mummy shaped.
- Sea to Summit Reactor Thermolite Liner - Another sleeping bag liner, this time made of thermolite fabric, which is a hollow core fabric more or less designed to add warmth as efficiently as possible. This particular liner adds about 15 degrees of warmth, and weighs 9 ounces, or 255 grams, which as you can see is a much better warmth to weight ratio than the Cocoon liner above. It's also a mummy shape.
- Sea to Summit Reactor Extreme Thermolite Liner - Another thermolite liner from Sea to Summit, this one intended for extreme weather. This one adds a very impressive 25 degrees of warmth to a sleeping bag, which will easily transform a summer sleeping bag in to a winter sleeping bag. It weighs 14 ounces, or 399 grams, which is about as lightweight as you're going to get without buying a whole new sleeping bag with a lower temperature rating.