Boots lack interior cushioning, the walls are covered with a thin material. How thin? Went on a hike for about 4 miles, city park, and it seems that my socks were hungry and ate the wall's material. The interior only provides proper padding for the upper part of the boot/leg not the ankle or foot; the boots felt warm for Feb in GA and I was wearing compression performance socks (not weather rated), so do not know much about the coolmax.  If I could I would return them, now that i am stuck with them a will probably just use with thick socks until they disintegrate or become unbearable. If they would treat the inside with the same kind of padding that even a normal tennis shoe has, these boots would be good. They did look nice, well still do if you do not look inside.