Ask the MB: Winter Hat
A: Besides being ubiquitous (in spite of Cuba Gooding Jr. signaling them as outgoing a while back), a flat cap vs. Chicago winter is the equivalent of scissors vs. rock. Same with a fedora.
In the winter months we advocate cashmere from head to toe, and if you can't currently swing a drawer full of $250 Maurizio Amadei cashmere boxers and $64 Paul Smith cashmere socks, start with the head and work your way down. This this 5+1_Annapurna ($98) and this Malo ($79) and this Bottega Veneta ($220) are all knit caps, but they're far from ordinary.