Living in GA, I was just about to ask the same question! I did do one pair on Cascade Fixation that aren't terribly hot. I have mixed feelings about it. I needed some for a class, and the didn't have a good color selection---so I think I might like it better in different colors than what I have. It was weird to work with, but the socks fit the best of any that I've made.
I am from GA & we can have all 4 seasons in one day here sometimes. I personally have used the SWTC's Tofutsie yarn & it isn't heavy for warm weather but it is warm during the cold weather, I should know I am a bus driver so I am in all the time. I also use the Cascade Fixation yarn for warmer weather & make just a footie sock with it since it is cotton & my feet don't sweat with it. Just my 2 cents worth. Hope it helps.
Jody in Powder Springs, GA
Mom of Alyssa(23) & Allen(20) & two spoiled Chihuahua's - Stitch (10) & Gizmo (8) Grandma to Hunter (8)
OTN: Socks! Socks! & more Socks! for me for winter. I drive a school bus. BRRRR!!
Crocheting: Ripple Stitch Afghan in collegiate yarn from Hobby Lobby for DH.
UFO's: Ballet Wrap Sweater with Ovation Yarn; this thing keeps stareing at me to pick it back up. Braided Wrap with Therapy Yarn.