During sweltering summer heat, we often imagine ourselves lounging in a comfortable T-shirt and a pair shorts. But sometimes, we need to class it up a little. And dressing well when the temps are up doesn't always mean throwing on a polo or lightweight woven shirt. You can have it both ways with a short-sleeved popover. This one from J.Crew combines a crisp button-down collar with a partial placket and interesting horizontal stripe pattern in muted colors. It's got a chest pocket to stow your shades, and can be worn untucked with shorts or with a smart pair of chambray trousers.