I brought these with me on a week-long camping/climbing trip and ended up having to use them at night when the temp. dropped below freezing (I have a really cheap sleeping bag and am a VERY cold sleeper). They worked out great, are very cozy and soft and stretch well. The sizing is a tad bit larger than usual so I'd order a size smaller if you're between sizes. The material isn't bulky or thick either, kind of like throwing on 2 pairs of lightweights.