I ride in the dunes during the summer when it is more than 100 degrees, and it works like a charm. I have ridden in all conditions: sub-freezing (ice racing , high humidity, low humidity, snow, rain, mud, sand, desert, high temperatures (100+), mountains, sea level...
Give it a try and I bet you will be pleasently surprised. :cool:
BTW: The cotton sock should be very thin, not a regular athletic cotton sock, and the wool sock should be about as thick as a normal athletic sock. I was not very clear before, maybe that is why you are skeptical... :ermm:
I also use that combination whenever I wear any type of boot or thick shoe (such as a hiking shoe) and blisters are never a problem as well.