Dress light. I ride hard but only for 8 miles each way, and I don't wear long sleeves unless it's in the low 50s. I don't wear long pants until it's in the 30s; tights under shorts for the 40s. You get the picture. You'll warm up pretty quickly. Coast for the last quarter-mile, and bring a bandanna to wipe away the sweat as soon as you stop. That way you won't stink.