Consider the following: 3.6-million cases of skin cancer are diagnosed in America every year and one in five of us will develop skin cancer at some point, according to The Skin Cancer Foundation. The best way to protect yourself is by covering up, but clothing doesn't necessarily block out UV rays. It all comes down to the Ultraviolet Protection Factor, or UPF – a measure of how much of the sun's radiation slips through your shirt.

The amount of protection an article of clothing provides is dependent on a number of factors, including tightness of the weave, type of material, and color of the dye. A white standard cotton shirt only boasts a UPF rating of about four, which isn't enough to keep you from getting burned. A high-weave UPF-50 shirt, on the other hand, guards you from 99 percent of harmful rays. (If a shirt doesn't have a rating, it hasn't been tested.)

Shirts with serious UPF ratings aren't a rarity – companies have been creating them for outdoorsmen for years. Until recently, however, most of them were boxy, uncomfortable, and awkward to wear. But, as the shirts below prove, it's possible to look smart on the trail and be sun safe.

Columbia Global Adventure Long Sleeve Shirt
UPF 50
There's a lot of technology built into this versatile long sleeve: stain and water repellency, sweat-wicking fibers, and treated elestane for maximum sun protection. Despite all the geek, both the solid black and white color options look sharp and could pass for a casual dress shirt if it wasn't for the bicep button for rolling up the sleeves. [$70; columbia.com]

Exofficio Minimo 
UPF 50
The shirt is comfortable and moves with you as you walk thanks to the vented seam running down its spine, which also aids air flow. The minimalist, wicking shirt also stuffs down to the size of a clementine, so carrying it in a pack is no problem. And the exciting and different combos of plaid colors are accented with roll up cuffs for a little pop. [$95; exofficio.com

Horny Toad Cardshark Shirt
UPF 35
The vertical, textured stripes and double-welted pockets on this shirt work equally well at a poker game as they do lounging poolside. The cotton-like fabric is a mix of polyester and Tencel, a yarn made from wood fiber, both treated with UV blocking [$79; hornytoad.com]

Outdoor Research Astroman Shirt
UPF 50
Rock climber Hans Florine wanted a collared short sleeve he could not only abuse on the cliffs, but also wear to the pub. OR's answer? A mix of durable nylon and spandex in a lightweight, breathable shirt that's tough and stretches several inches in every direction. The collar flips up and buttons to protect the back of your neck; the light checker pattern and almost invisible snap buttons keep things casual. [$85; outdoorresearch.com]

Prana Terrain Long Sleeve
This classic plaid shirt pairs well with most outfits and features a modern, slimmer cut (it fits small, so size up). Its organic cotton, polyester blend is the most natural feeling of all the mixes we tested. It also has the fewest flourishes: just some slight gusseting behind the shoulders to improve mobility. It has no stretch, wicking, or venting. [$75; prana.com