I am always surprised when I put this shirt on because it truly cools my skin on contact. I'm not sure what these shirts are made, but there may be some type of magic imbedded in the fabric. This is a shirt you have to try on to really understand for yourself.
a. The Cool Breeaze yarn is specially constructed in a flat shape to increase contact with the skin; it is also channelled or grooved to permanently move moisture from the skin, and is derived from elements which noticeably increases the cooling effect on the skin: these elements from which the yarn extruded, are designed to absorb and remove heat from the skin at a higher rate than other synthetic yarns. ( The yarns have a higher “thermal effusively" than usual synthetic yarns)
b. The difference between the cooling effect of a regular synthetic or natural yarn and the Cool Breeze is noticeable to the touch, when the fabric is dry: and this difference increases substantially when you sweat and when you are exposed to wind or your move from a static state to an active state. All of this is clearly exhibited in the new ASTM D 7984 test which rates Thermal Effusivity of any material. Thermal Effusivity is defined as the capacity of a material to conduct thermal energy. As an example, if you touch an object made of metal in a room at room temperature, it will feel much ‘colder’ to the touch, than a wood object in the same room at the same temperature. The higher the Theramal Effusivity co-efficient, the greater the capacity of the material to conduct thermal energy and the ‘cooler’ the effect.