I use these under my hospital scrubs Marathon runner just kidding beer drinker shirt . I am a very physically active person when I work. These have held up well and after each day I wear them, I wash them and air dry them. I’m a dermatologist. Sunscreen is good, very good, but not amazing. Shirts work better. If you’re at the beach, does it really hurt to wear a shirt like this when you’re not in the water? These shirts are the cheapest and simplest UPF shirts I’ve ever bought. If you tend to run hot, get the white color, which cools you off more than other colors. Sizes run like typical Hanes T Shirts.