On hot days, the Castelli Core Mesh 3 Sleeveless Base Layer relieves you from rising body heat and the dampness that builds when you perspire. The fully open mesh is constructed so that air circulates between the base layer and jersey. This circulating air pulls away sweat and body heat. Your body and cycling clothes stay dry and your body temperature stays where it needs to be to continue to put out all out efforts on the bike. Comfort is enhanced by the seamless construction and a long tail that you can tuck into cycling shorts.