Why Sun Shirts?

Sun shirts are probably one of, if not my favorite, pieces of gear. These shirts offer essential protection from harmful UV rays, helping to prevent sunburn and reduce long-term skin damage. I wasn’t a star performer at sun protection when I was younger, and now being more in tune with taking care of my body, sun shirts have become a staple of my adventure kit, allowing me to enjoy the trails without worrying about the lasting effects of sun exposure.

When you're out on the water or adventuring at high altitude, having the right gear is essential. I’m always in a sunshirt, so I was stoked to try out the Mammut Selun FL Sun Hoody, a lightweight, sun-protective layer that’s designed to keep you comfortable and your skin safe during long days in the elements. Whether you're climbing, hiking, or just enjoying the outdoors, this hoody has you covered—literally!

Key Features

• UPF 50+ Sun Protection: According to SkinCancer.org, “Ultraviolet Protection Factor (UPF) indicates how much UV radiation (both UVB and UVA) a fabric allows to reach your skin. For example, a UPF 50 fabric blocks 98 percent of the sun’s rays and allows two percent (1/50th) to penetrate, thus reducing your exposure risk significantly.”

  The sun is relentless at higher altitudes, and the reflection of the sun rays off of the water can be killer. With the Selun FL Sun Hoody, I know my skin is protected because of the UPF 50+ it provides. This feature makes it a perfect companion for sunny mountain treks at altitude or multi-day rafting trips.

• Quick-Drying Material: Made from a blend of recycled polyester and elastane, this hoody wicks moisture and dries quickly. It kept me comfortable when I worked up a sweat, and dried quickly when I got soaked SUPing. 

• Lightweight Design: The Selun weighs in at just 170 grams (for size medium), meaning it won’t weigh you down as you climb or hike. It’s an ideal layer to pack for multi-day trips or wear during high-energy pursuits.

• Comfortable Fit: The athletic cut moves with you, while the stretchy fabric provides a bit of give where you need it most. The long sleeves and thumbholes are a nice touch for extra coverage and comfort. I always glob sunscreen on the top of my hands, and this adds another layer of sun protection.

Performance in the Field

I took this hoody on a recent trip to Jackson Hole where the days were sunny but the air was cool. It handled both brilliantly. The UPF 50+ rating gave me peace of mind under the high-altitude sun, and the lightweight fabric was perfect for layering without adding bulk.

The hoody’s breathability was a standout feature. Even after hours of hiking switchbacks and climbing on sun-soaked rock, I didn’t feel like I was overheating. Plus, its quick-drying fabric came in handy when I worked up a sweat. It dried faster than I expected, meaning I wasn’t stuck with a damp layer for long.

I have some major holes in a few of my sunshirts–  and I don’t think this will be one of them. It feels more durable than some of my other shirts, like the weave of the fabric is able to handle more rocks and tree branches that may come its way.

This is the first sun shirt I’ve tried that has a collar, and when I was wearing it stand up paddle boarding and the wind was whipping, it added an extra layer of protection and kept my hair from flying in my face. It also helped keep suns damaging rays off of my neck– an area on the body that is often forgotten when doing the ol’ sunscreen douse. 

Style Points

The sleek, minimalist design and athletic cut make the Selun FL Sun Hoody not just functional but stylish, too. It’s available in a few neutral tones, so it pairs well with just about any outdoor fit. Whether you're taking summit selfies or snapping pics of wildflowers, you'll look the part.

The Verdict

For outdoor enthusiasts looking for a versatile, lightweight sun hoody, the Mammut Selun FL is a top-notch pick. With its sun protection, quick-drying material, and easy-to-pack design, it’s perfect for everything from high-altitude treks to long days wake surfing. Keep this layer handy, and you’ll be ready for whatever the trail (or the sun) throws your way.

Pros:

• Excellent sun protection (UPF 50+)

• Lightweight and breathable

• Quick-drying fabric

• Collar for extra sun protection

• Comfortable athletic fit with stretch

Cons:

• Limited color options for those who prefer brighter, bolder hues

This hoody makes the perfect companion for sun-filled days outdoors—whether you're climbing, hiking, or rafting your favorite river.

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