Nothing new. Romans wore a sock-like covering for the foot called udones
in cold climates from an early time. They have been excavated, preserved in surprisingly good condition, along the Rhine frontier (Mainz and Trier, etc.)
@ Belisarius: Making fun of "socks with sandals" brings up a cute story.
Some years ago I was at a Roman army re-enactment event (not participating) with two nephews of mine - ages 11 and 10 at the time. They both thought the army boots - caligae
- were pretty cool, and it would be fun to dress like the soldier re-enactors.
One old grizzled "centurian" had udones
with his army sandals, and the kids were puzzled. He explained that the Romans were most often in the north along the military frontier where it was cold. They were worn for protection.
The 10 year old said "Eeeew, gross!"