Construction Woven of 80% cotton and 20% 37.5(R) performance yarns (polyester). 37.5(R) technology releases excess heat and humidity, preventing it from becoming trapped within your microclimate. Works immediately and continuously while you sleep to either trap heat when you're cold or evaporate excess heat and humidity when you're warm. Body heat activated performance, providing comfort personalized to each sleeper's need for warmth. Moves heat away before sweat can form, minimizing swings…