When I run during the winter months, I’m always careful to have my core layered up like King Tut, which is how I found myself working out last month in a room where the temperature had been dropped to a freezing 30 degrees.

I was test-driving Nike’s new Therma-Sphere vest, which is made out of fabric with an inner honeycomb design meant to trap heat in your body for cold-weather training.

Despite the chill, I warmed up within a few minutes of lunges and never felt the need to adjust the vest, which felt more like a second skin. The construction is lightweight and water-resistent, and kept me dry throughout a punishing series of sprints, jumps and medicine-ball tosses.

Plus, the garment has an asymmetrical zipper and a very cool, sleek look. So even when I’m not getting a workout, it will look pretty spectacular with jeans and boots.

Nike Therma-Sphere Max training vest; $155 at nike.com