All-day activities? No sweat in this advanced chill-summer long sleeve. Stay cool and covered with this performance shirt, featuring advanced sun-deflecting fabric that packs UPF 50 protection. Its moisture-wicking properties help keep things dry and comfortable. Columbia offers this women’s long sleeve in multiple colors and sizes. Regular Fit. To ensure the size you choose is right, utilize our sizing chart and the following measurement instructions: For the sleeves, start at the center back of your neck and measure across the shoulder and down to the sleeve. If you come up with a partial number, round up to the next even number. For the chest, measure at the fullest part of the chest, under the armpits and over the shoulder blades, keeping the tape measure firm and level.