I'm a teacher and bought this shirt to protect me from the sun when I'm outdoors with the kids. I cannot wear sunscreen as it irritates my skin, and I have no tolerance for heat & humidity. This shirt solves both problems very well! Direct afternoon sun for 3 hours doesn't affect me in the slightest with this shirt. Breezes flow through it, keeping me blissfully cool and comfy. Paired with a nice wide-brimmed hat and some sunglasses (see llbean.com !), I'm good to go.