If Goldilocks knit socks, Solemate would be her pick because her feet would be "not too hot, not too cold, but just right!"  This sock yarn utilizes Outlast, a fiber technology developed for NASA, which allows it to respond to skin temperature to manage heat and reduce moisture.  Seriously, sock yarn has come this far. Size is approximately 425 yards/ 4 ounces. 55% superwash merino wool, 30% Outlast, 15% nylon. See product page for more details. Fingering weight.