Thermolite is a DuPont fabric made with hollow fibres that insulate without bulk. A midweight sock, these are a step up on summer socks as far as keeping your tootsies warm and they’ll still fit inside your race shoes.
Thermolite is the perfect layering fabric that provides warmth and comfort without weight, even when wet.
Hollow-core fibers trap air and allow greater insulation
Also the larger surface area allows for faster evaporation by speeding moisture away from the skin to the surface.