Warm, but not like the original - I recently bought this base layer pant thinking it would be a parallel replacement for the Chlorophylle pant that looked a lot like this one that I bought a few years back which I loved. Unfortunately, even the large was too tight, the legs are short...generally a really odd fit. The waist band is more like you would find on underwear and already some of the stitching came out along the waist band. A bit disappointed...I was going to return but decided to hang on to them....maybe they will stretch in time, but I don't think so. I wish they still carried the base layer pant that I got from them a few years ago...