At a Derek Lam trunk show at Winnetka boutique Neapolitan Collection, the hot-ticket item — fall vests, retailing from $1,500 to $5,000, rendered in knit and suede, leather and hair calf — may come as a surprise for a city known for its bone-chilling winter weather. But not to Lam.

“Women love outerwear like vests. They’re driving. It’s not like in New York City. [In Chicago] they’re going from the car to the destination. They need comfort when they’re driving and they don’t need all the bulk, but they want the coverage,” said the designer, who launched the five-day trunk show that took place from April 14 to 18, at the store. As a designer, “you need to go and understand how the client lives their life otherwise you’re only understanding how a New Yorker lives.”

Chicago is one of the designer’s best markets, Lam said, adding that he really looks forward to meeting with his clients one-on-one. “My favorite part is just reconnecting with the clients — they’ve become really nice friends,” Lam said. “It’s always nice to go and explain from a personal point of view what I’m designing, spend some time with the ladies, get them fitted and walk them through the collection.”

For fall, other top-selling items at the trunk show included the designers’ high-waist trousers, knits with suede trim and double-faced bi-colored peacoats, noted Neapolitan Collection owner Kelly Golden, whose store has carried the designer’s collection since 2004.

Golden declined to give sales figures for the trunk show, but said “Derek has not only become one of our biggest businesses, he’s also become a good friend who knows our clients and their lifestyle,” Golden said.