Review on Ultralight Sleeping Bag Liner By The Friendly Swede - Perfect For Hotel And Camping, Travel Sheets, Adults Sleep Sack, Microfiber Cotton Feel Travel Sleeping Bag - Pocket-Size With Stuff Sack by Nick Childs

3/20/2018 updateI didn't expect the manufacture to respond to my review. I'm changing it to a 5 as my interpretation of their product was not correct:Our liner is not necessarily designed for warmth and is simply designed to keep your sleeping bag clean and can also be used on its own in hotter climates. As I mentioned in response to your review, we are working on releasing our liner in different styles and materials including one that will be more designed for warmth but since those options aren't yet available for you to try out, we have provided you with a full refund on your order to make up for any disappointment.Original post:Its ok. I have a sleeping bag I bought for long back pack trips that is rated around 30 degrees. Its close to 1lb so its great for portability/pack-ability. But many nights in Colorado, the temps drop. I bought this as its light weight very packable, but it only added a little protection during cold nights. I would say its better than none, but not by much.On the fence if I would buy it again. I'll probably take a large trash bag next trip