These socks are amazing! I wore them in tennis shoes on a 90 degree day and my feet stayed dry and comfortable. One thing to keep in mind is they are actually quite short. I originally bought them for hiking but found out they were a little to short for my boots. I kept them anyway because they make an amazing hot weather sock. They can be quite warm when it cools down as well. I bought the Smartwool ultra light crew sock as a result of the shear amazingness of this sock.
"Awesome pair of socks and don't overheat even though it is wool"
TESTED TO THE EXTREME. I started out wearing them in my leather work boots for an 8 hour shift. Constantly moving and feet were dry at the end(unlike other socks I've used). I didn't stop there though... I CONTINUED wearing them for 2 MORE DAYS! At the end of three days they were not stiff, and did NOT smell. A friend verified these two facts. lol. Anywho, great product and while I don't think I will ever wear a sock again 3 days straight, it is nice to know I have the option to if need be.