A handful of summers ago I helped lead a group of backpackers on a magical trip to Mount Silliman and its namesake lake, located on the lofty divide between Sequoia and Kings Canyon National Parks. We talked about a lot of stuff out there—food (naturally), gear (of course), and poop (obviously). But we also couldn’t stop commenting about how damn hot it was, especially as the relentless sun bounced off of more than a thousand feet of steep granite slabs underfoot during our ascent.
During what might have been the group’s second or third collective sunscreen application, someone joked about how we were all just poisoning ourselves. A few chuckles emerged, but the humor was a bit dark—after all, it was only a few months back that the Journal of the American Medical Association published the results of an FDA study that concluded several common components of chemical-based sunscreens (avobenzone, ecamsule, octocrylene, and oxybenzone) didn’t simply linger on our skin; they were actively absorbed into our bodies after application.
Even though the FDA has since tasked sunscreen manufacturers to conduct their own studies on the absorption rate and safety of their chemical components (natural materials like zinc oxide and titanium oxide are already considered safe) by November, those original findings are worrisome. One of those big four sunscreen ingredients, oxybenzone, has a rather notorious legacy—not only has it been proven toxic to marine life, especially corals, but past studies have shown possible correlation to hormonal imbalances, low birth weight, and infertility in humans.
Of course, ample use of sunscreen, including the chemical stuff, has also proven an effective means to prevent skin cancer. So what’s an avid outdoorsperson to do while waiting on further study results to emerge? Slather up with mineral sunscreens, sure—but also consider adding a layer to your adventure wardrobe: a sun shirt.
I’ll admit that I used to be a skeptic—why should I buy a special piece of clothing when I have plenty of other long-sleeved shirts hanging around in my closet? But then I learned that sun-protective clothing isn’t just a marketing ploy; it’s manufactured to actually prevent (most of) the sun’s UV rays from hitting your skin.
Here’s how it works: first, clothing by its very nature is a general line of defense against the sun’s UV rays, but not all clothing is created equal. Pieces specially designed for the purpose will bear a UPF rating—that’s ultraviolet protection factor, sort of analogous to the SPF rating on a bottle of sunscreen. Your basic light-colored cotton tee has a UPF rating somewhere in the neighborhood of 5; what that means is that UV rays will penetrate at a rate of one out of five, or 20 percent. The higher the UPF rating, the better the protection—50 UPF will block 98 percent of the UV rays (and that’s both the UVA and UVB types) from passing through the material.
This magic UV fortress effect is courtesy a number of factors, and each garment will utilize these differently. The fabric itself is important—some, like polyester and silk, will actually physically deflect the damaging rays; others, like cotton and linen, act as a sort of UV welcoming mat. Fabric weave is also crucial in creating a physical barrier—the denser, the better. Some sun shirts are also strengthened with treatments, both chemical and mineral (zinc to the rescue once again!), and color itself lends a hand to the defense—contrary to the popular notion that light colors are best in the sun, darker (and brighter) ones will better absorb UV rays. Finally, sun-protective shirts usually feature at least a few construction trademarks, including hoods, high necklines, protective cuffs, thumb loops, and a loose fit.
Like I said, I used to be a skeptic—for years, I hiked, climbed, and backpacked in a series of increasingly dingy button-down cotton shirts scored from local thrift shops. And sometimes I went completely sleeveless. But then I paid for my nonchalance during a trip when I was left nursing two painful forearms filled with oozing sun blisters. And not too long after that, I needed to have a sketchy mole removed from my back. Finally convinced, I promptly made my way to the nearest REI to purchase their Sahara shirt, a much sturdier button-up complete with a UPF factor of 35 and a dork factor of 100.
I still have that shirt, which does the trick when I want to act out my human mullet fantasies (in case you’re wondering, that’s business on top, snake-print running shorts on bottom), but I eventually snagged something a bit sportier—Patagonia’s much-beloved 50+ UPF Sunshade Hoody ($79). Though it was originally designed to wear while fishing, I actually found out about the shirt through my climbing buddies, since nearly all of them seemed to own at least one, since the material (100 percent polyester, more than half of it recycled) holds up relatively well against rock abrasions and the hood stretches perfectly over a helmet.
This past weekend, however, I was wearing my new all-around favorite—Ridge Merino’s Solstice Hoodie ($80). At 25 UPF, it has only half the protective power of the Patagonia version, but the first time I slipped it on, the shirt felt like an old friend. The tightly woven merino wool (cut through with a small percentage of nylon) sat soft against my skin, the fit draped perfectly whether or not I was wearing any other layers underneath, the hidden thumbholes extended the sleeves to the base of my fingers, and the lightweight fabric served as a wicking powerhouse that kept me cool. Plus, I could wear it around town without feeling like I’d just emerged from the pages of an outdoor gear catalog.
So, yes, I went ahead and reapplied my (mineral) sunscreen that day on the mountain, but I also tugged my sun shirt’s hood over my baseball cap, just as a few others in my group did with their own. And then I got back to the good stuff, helping a bunch of people stay safe and have fun as they pushed their limits in the beautiful—and very sunny—alpine wonderland of the Sierra.
Top photo: Helly Hansen
More sun shirt goodness
The Mountain Hardwear Crater Lake Hoodie is light, soft, and boasts a 50+ UPF rating. $48-65.
We’re big fans of the Patagonia Capilene Daily Hoodie. Avail in women’s and men’s sizing. *Note: Patagonia recently learned that the UPF ratings of their Capilene Daily shirts are incorrect, with some shirts receiving higher UPF ratings than they actually deliver. Patagonia insists the shirts still offer some sun protection, but they are issuing a voluntary recall of many parts of their Capilene shirt line. You can read about the issue, here.