- Familiarity: I've used it once or twice and have initial impressions
To say this liner LITERALLY changed my life might be an overstatement but it DID dramatically improve my sleeping experience during a January camping trip, where the temps dropped to the high teens low 20's (Fahrenheit) at night. My feet get so cold at night even when it's not freezing, so adding this liner to my sleeping bag was a game changer. I added a hand/foot warmer the second night, and slept straight through til morning - no cold feet! This liner is also cozy enough that I might use it alone for a spring/summer bag in the mountains.