My socks are actually cooler than the thicker cotton socks I sometimes wear. I can actually feel the wind blow through my canvass sneakers when I ride my scooter. I will avoid wearing the black ones when in the sun, as dark colors absorb the sun's heat much more than white ones.
Personally. I wear these at my work where I have to wear leather shoes and I'm on my feet walking all day long. For me they don't make me feel like I'm overheating but my feet definitely get sweaty by the end if the day.