Wallace & Barnes, $118

The summer heat is starting to subside, but unfortunately it's the time of year when you can be shivering in the morning and sweating by lunch. Which is why we're grateful for the shirt jacket. The heavy-duty, hard-wearing overshirt will serve you just as well on 40-degree nights over a sweater as it does on 60-degree days over a T-shirt. And while you could likely find some nice vintage versions of a chore shirt out in the wild, today's best versions have the advantage of a more modern fit. It's got to be just right, you see—roomy enough to sandwich between your button-down and a coat on cold days, but tailored enough to sport by itself over a plain T-shirt. Trust us, you'll get more use from this ideal layering piece than you might expect.