We've all seen runners dressed in singlets and shorts in 40-degree weather—but don't worry, they're wearing gloves! On the surface this doesn't make much sense, but the reason is fairly technical.
When you're running, most of the blood is pumping to your legs and core. This means not as much blood is circulating to your hands and fingers, keeping their temperature lower. The same goes for your head, which is why you also see many elites clad in a hat and gloves, no matter how little clothing they wear elsewhere.
Gloves are an easy way to keep your extremities warm before and during the race. We recommend a cheap cotton pair (Target sells a three pack for less than $10), so if you heat up, you can throw them to the side. Keep your eyes peeled at the expo, as brands frequently sponsor freebies.