2XU Microclimate Headband ($25, 2xu.com)
Perfect for those days when you’d like to keep the chill off of your ears but don’t want to overheat by wearing a full-on insulated hat, the Microclimate Headband provides just enough coverage for moderate weather. The one-size-fits-all headband was slightly snug on our tester’s head but stayed firmly in place even during intense exercise. The synthetic material effectively moved moisture away while small holes close to the ears added extra ventilation. The tester found this headband also worked well on the bike.