New Balance Icefil Short Sleeve
The Icefil is formulated to reflect UV rays (consider how hot you get in a black T-shirt versus a white one). Then, for an added chill, New Balance treated the fabric with Xylitol, a sugar alcohol usually found in minty-fresh gum and toothpaste, which creates a cooling sensation that's triggered by sweat. Think of it as an Altoid for your body.
—By Natalie Gingerich