: Thick socks actually cut off circulation and make your feet colder. Use a dedicated wool or synthetic ski sock.
Flex refers to how difficult it is to bend the boot forward. There is no industry standard, so a "100 flex" from one brand might feel different than another, but generally: buy mens ski boots
: Do not rely on your sneaker size. Use a Brannock device at a ski shop to get your exact Mondo size. : Thick socks actually cut off circulation and