I am a thin woman and I was hoping for a bag that would pack small and keeping me warm to 20 degrees. Well I went camping with a low of 26 and I did keep me warm, although I doubt it would keep me warm much below 20 degrees which is what I was hoping for! So if you're bigger or a man this will keep you warm closer to 0 degree as advertised. I am also pleased with how light it is and how small it packs so for the price I am happy with this purchase.