As an avid hiker I was used to wigwam socks for colder weather. However, my friend recommended smartwool socks and I have to say that I have never chosen anything else. The feel of the material is amazing on your foot, and the construction and material used is incredibly light but heat retaining. If you need to size up on a boot, this sock is perfect as it adds around 1 cm around your foot. For outdoorsy purposes these socks are amazing, and for more casual cold weather wear it is also appropriate. The only downside is that these socks may fit a little big depending on how you size.