Natural fibers are considered some of the best fiber types you can wear for your daily activities, and cotton is beloved for lots of reasons. In the fashion industry, cotton is known for keeping you cool, being soft on your skin, and is generally considered more sustainable than polyester or other synthetic fibers.
But the same characteristics that make cotton great for daily wear are some of the same characteristics that make hikers, campers, and other outdoor enthusiasts say that “cotton kills.” Let’s spend some time looking at this soft, fluffy fiber and finding out why it’s so dangerous to wear on a hike!
Cotton cloth is the spun fibers of the cotton plant. These fibers are almost entirely cellulose. The fibers are also hollow tubes with several outer layers per fiber, creating millions of tiny pockets. These two features make cotton an extremely absorbent material.
First, cotton fibers are about 99% cellulose. Cellulose has numerous hydroxyl groups, each of which has a slight negative charge. Since water has a slight positive charge, it is attracted to these hydroxyl groups, which makes cellulose– and therefore, cotton– extremely absorbent.
Secondly, while the pockets and tubes in cotton fibers can trap warm air, that air is easily displaced by water. Cotton fiber walls collapse when wet, making the wet cotton stick tightly to your skin and making it harder for the fabric to dry.
People have been saying that cotton kills for years, because wearing cotton means that you are at higher risk for hypothermia. When you’re planning a hike, you don’t always think about the risk of being too cold. It’s more likely that you’ll worry about overheating– which is also dangerous. But hypothermia can sneak up on you, especially if you’re wearing cotton next to your skin on a cold day.
Cotton is absorbent, but not moisture-wicking. This means that cotton absorbs sweat, but doesn’t move it away from the skin. Instead, it quickly becomes saturated and holds the moisture in place. This makes your sweat less effective, since cotton slows down the evaporative cooling process.
It certainly can. Hypothermia is actually more of a risk in summer than in winter because people don’t expect it. For summer hiking, you should wear a lightweight shirt in a moisture-wicking material. Quick-dry synthetic fabrics are perfect for summer base layers, since they are light, breezy, and moisture-wicking.
So what should you wear instead of cotton? You should choose base layers made of fabric that is:
With that in mind, some of the best cotton alternatives are merino wool, synthetic fabric, and high performance fabric blends.
Merino wool is a great alternative to cotton. Merino wool is lightweight and soft, like cotton– but unlike cotton, wool can keep you warm even if it gets wet. It is a popular material for socks and base layers. Merino is a high performance fabric with natural moisture-wicking properties. It is softer and more comfortable than many other types of wool, too.
Polyester performance fabrics are also good alternatives to cotton. Polyester refers to any synthetic fabric, and these fabrics can be highly engineered for good performance in the backcountry. Synthetics dry quickly and are very lightweight. The fibers aren’t hollow, so this type of material can’t absorb moisture as well as natural fibers– which means they dry faster and are more effective at wicking away moisture.
Blended fabrics combine the best qualities of their components and make up for many of their weaknesses. Popular blends include wool/polyester, blended types of polyester, bamboo/polyester, and nylon/polyester. Cotton/polyester blends also exist, and while they are better for hiking than plain cotton, it’s still best to avoid this fiber whenever possible.
| Merino Wool | Synthetic Fabrics | Blends | |
| Price | Most expensive | Budget-friendly | Depends on the blend |
| Performance While Wet | Retains insulating properties while wet | Does not insulate while wet, but dries very quickly | Wool blends retain some insulation while wet |
| Moisture-Wicking? | Yes, but not as effective as synthetic fabrics | Yes, very effective | Yes |
| Comfort | Very soft and lightweight | Soft and lightweight; some people’s skin may react poorly | Very soft and lightweight; exact comfort depends on blend |
| Odor Retention | Does not retain odors | Can retain odors; wash regularly | Wool and bamboo blends retain fewer odors |
| Sustainability | Grows annually on sheep | Technically made from plastic; sheds microfibers. Can be made with recycled material. | Varies widely by blend- bamboo/wool fibers are more sustainable than synthetics |
When you’re choosing hiking clothes, no matter the season, you should avoid cotton and choose your layers carefully. As you’re picking out your wardrobe, consult the following articles for our best advice on staying comfortable as you hike:
Hiking clothes are made in lots of different fabrics. For complete guides to your fabric options, check out the following articles:
You have lots of choices when it comes to your hiking gear– but when it comes to cotton, there’s always a clear choice. Just say no, because cotton kills!
