I am a bg fan of merino wool. Super comfortable, and super temperature comfort range -- warms when needed, but not hot when the weather is. These are the most light-weight wool socks I have been able to find, a bit thinner than typical athletic socks, which contributes to the not too hot part of the equation. Also, thinner socks give you a more solid connection between foot mechanics and shoe. They fit my foot well, but are a little tight going up the leg (crew sock height). It's not uncomfortable, but it is a little hard to get them on and off. I imagine if I went to larger size, that minor issue would be solved, but the fit on the foot might be too loose -- just guessing.