In the twentieth century, designers took two distinct approaches to imagining the future of fashion. The first approach tended toward metallic, geometric, quasi-robotic styles: think Pierre Cardin’s space suits of the nineteen-sixties, inspired by the first moon landing. The first generation of high-tech wearables look a lot like what those designers predicted. But the designers of the past had another vision, too, and this one could be a big, untapped market: making clothes better serve their original purpose of keeping people warm, dry, and protected. One designer, in 1939, envisioned that decades in the future women would wear an electric belt that would adapt the body to unpredictable weather changes. It’s an attractive idea for anyone who has sweltered on the subway, then spent the rest of the day shivering in an air-conditioned office. Along those lines, a group of M.I.T. graduates have designed a ninety-five-dollar dress shirt that borrows from NASA’s space suits—not the bulky styles themselves, but the technology in their materials—to store heat away from the wearer when it’s too hot outside, then return it when temperatures cool. It isn’t hard to imagine Apple using its technological prowess to weave computers right into clothes, especially if it draws on the fashion sense of Ahrendts and Paul Deneve, the former chief executive of Yves Saint Laurent, whom Apple hired last summer to focus on special projects.