With summer in full swing and many of us eager to get out and enjoy the warm weather during these months, it can be easy to forget the importance of protecting yourself against the very thing that causes that warmth: the sun. Yes, that giant, glowing circle in the sky does beckon us to enjoy the outdoors in a variety of ways, but it can also cause sunburn and sun poisoning is you’re not prepared for it. Sunscreen and drinking lots of water can help, but did you know there are also clothes that help protect you against the sun while you’re on the trail, as well?

Fabric and knits that consist of tighter construction minimize the space between yarns, which reduces the amount of UV light that can pass through to your skin. Some tightly constructed UPF-rated clothes also use vents to boost air circulation and help you stay cool. Also, thicker fabrics also help reduce UV transmission.

Along those same lines, the type of fiber used in the clothes can play a role. For instance, polyester does an excellent job at disrupting UV light, as does nylon. Wool and silk are moderately effective, but fabrics like cotton, rayon, flax and hemp are not.

Some think that a garment’s color can have an effect on its sun defense, when it’s in fact the specific type of dye used in the garment that impacts a fabric’s effectiveness. Some dyes deflect more UV radiation than others, and some absorb none at all—including black dyes. The higher the concentration of such dyes, the darker the garment becomes, so it can be darker, but ultimately color has no influence on UV rays. However, the only real way to know what you’re dealing with in a given piece of clothing is to check its UPF rating.

There are also several kinds of treatments a piece of clothing may be subject to that can boost its ability to protect against the sun. For example, chemicals effective at absorbing UV light may be added during processing, and specialized laundry additives, such as brightening agents and UV-disrupting compounds, can boost a garment’s UPF rating, as well.

Now, even with the factors listed above, there are still ways you can reduce a garment’s effectiveness. For example, stretching a piece of clothing too much If a garment increases the space between yarns, and its effectiveness against UV light can see a major reduction. Also, a fabric’s ability to disrupt UV radiation can be reduced when wet, so remember to peel off that shirt when you see an inviting lake or river. Lastly, clothes that have seen a lot of trail time and become faded or worn out won’t do as good a job of protecting against the sun as they once did.

Sunscreen and wide-brimmed hats are still good ideas when hiking in hot, sunny weather, but you’ll also want to invest in a few articles of clothing designed to fight the sun’s rays, as well. Frequent hikers or those living in warmer climates will find their qualities to be a great bonus on the trail, and the added comfort will make your hiking experience that much more enjoyable.