Most long-sleeved sun shirts feel suffocating in summer temps—but not the Solar Polar. It uses flat (not round) polyester yarns, which increase the surface area of fabric touching your skin to transfer sweat faster. “It kept me comfortable in direct sun and 85°F temps,” says one tester, who issues props for the shirt’s UPF* 50 coverage (which eliminates the need to slather sunscreen repeatedly on long treks). A deep, 14-inch zipper let her enjoy cooling breezes while cranking out steamy bike rides. Downside: Some testers balked at the torso-hugging, superhero styling. $70; 5 oz. (w’s S); columbia.com
*UPF (Ultraviolet Protection Factor) Unlike SPF, it measures protection against both UVA and UVB rays.