Featuring 2XU's revolutionary ICE X Polyester with Xylitol and IR blocking technology to inhibit heat penetration, this impressive Run Singlet is anatomically engineered to achieve the ultimate in moisture management. High level protection and thermo-regulation is also assured. ICE X fabric is engineered for endurance events like no other. Xylitol is embedded in the fabric yarn to draw heat from the body and IR blocking inhibits penetration of infrared rays to lower skin temperature by up to 5.4 degrees farenheit. This garment will excel in all conditions, especially keeping you cool when it's hot outside.