A frequently asked question in whitewater river sports is, “What material provides warmth even when wet?”
Today, we’re going to answer that question in addition to questions about other materials like polyester fleece that can help you stay warm when wet.
Retaining body warmth in river sports is crucial to staying safe and enjoying the adventure. This is especially true in rafting when battling fierce rapids with the possibility of falling in.
That’s why we recommend wearing wool, polyester materials like fleece, or a combination of the two for fabrics that best provide warmth when wet.
This article will discuss some of the best materials for keeping warm after getting wet so you can stay safe and comfortable.
What is the Best Material To Keep You Warm When Wet?
Wool is the best material to keep you warm when wet and is an essential piece of clothing you should wear when rafting.
Wool is a natural, time-tested material made from sheep fleece. It has excellent insulating properties, even when wet.
Unlike fabrics like cotton, a textile that sucks heat away from your body when wet, wool creates heat when damp and passes it back to your body.
The science behind it is called water adsorption. This process involves a temporary chemical bond between the water and the molecules in wool. This bond creates an exothermic event, which releases heat.
Does Fleece Stay Warm When Wet?
Fleece clothing, also known as Polar Fleece, is another excellent choice for keeping you warm when wet. Fleece is a synthetic fabric made from polyester or a polyester blend designed to keep you warm like wool.
Polyester is a material, like wool, that helps you stay warm when wet.
During manufacturing, fleece fabric is “brushed” to increase its volume and make it feel fuzzy like wool.
The benefits of fleece clothing include its lower price point than wool and its ability to withstand wear and tear. Some of our best fleece layers are over 10 years old and have seen many days of rigorous use, all while helping us stay warm on the river.
While performance clothing and rafting gear companies sell high-end polyester fleece clothing, inexpensive fleece from discount outlets or Amazon typically works just as well.
Does Cotton Keep You Warm When Wet?
Cotton is an excellent material for many purposes; however, it performs poorly in retaining and providing warmth when wet.
Cotton is a material that absorbs water, effectively diluting it rather than bonding its cotton molecules to it. This process does not release heat but instead remains cold. If left on your body too long, a cotton layer will begin sucking the warmth out of your body.
As such, wool or fleece/polyester are both warmer than cotton when wet.
One of the main safety tips for rafting or exploring outdoors is to leave your cotton garments at home. In many situations, cotton can be a dangerous fabric to wear when wet.
Down is another material that doesn’t retain insulating properties when wet. We’ll only wear down when rafting if it is under a properly fitting dry suit in the coldest of scenarios.
Does Down Stay Warm When Wet?
Down is an incredible material for insulating your body when it is dry. When down gets wet, it unfortunately loses its loft and depletes any insulating properties.
Down works by trapping air close to the body, allowing it to heat up. However, it cannot trap much air without loft.
As such, we don’t typically recommend wearing down when on the river due to the risk of it getting wet.
Is Wool or Fleece Warmer?
Both wool and fleece stay warm when wet, and each has its distinct benefits.
Wool of equal thickness as a fleece fabric should keep you at approximately the same temperature.
However, wool will repel more water initially because of a naturally occurring water-repellant chemical in wool called lanolin. A downside of wool is that when it is entirely wet, it will take longer to dry than synthetic fleece.
Either way, both fabrics are better than cotton and are good choices when entering wet environments or participating in river sports.
Best Mid-Layers for Fly Fishing: Wool or Fleece?
As river enthusiasts obsessed with rafting and fly fishing, we’ve found that it’s always best to be prepared with the proper clothing.
This includes rafting through violent rapids, float fishing on mellow rivers, and walk-wade fly fishing.
Fly fishing doesn’t typically involve getting your body wet, although freak rain storms on the river can come out of nowhere at any time.
Further, it’s entirely possible to fall into the river when fly fishing, making a wool or fleece base layer an essential piece of angling gear.
When fly fishing in warm weather, we like to wear a synthetic base layer on top and wool long underwear on bottoms under a set of waders.
When fly fishing in cold, rainy weather, we wear the following:
- Synthetic wool base layer. We like Merino wool products.
- Fleece mid-layer.
- Non-down insulating layer or rain jacket.
- Wool or synthetic long underwear base layer.
- Insulating pants over the long underwear (non-cotton sweat pants or joggers work well).
Do You Have to Buy Expensive Clothing to Stay Warm When Wet?
Wool clothing will inherently be more expensive than fleece or polar fleece. However, both are great options for rafting in cold, wet conditions.
Pairing a wool base layer with a fleece mid-layer is an excellent option for rafting in cold conditions.
Many great wool and fleece products are available from rafting and outdoor companies such as Immersion Research, Smart Wool, Darned Tough, and Patagonia. However, if budgetary constraints don’t allow for a high-end product, you can find excellent fleece and wool products from big-box outlets such as Wal-Mart or online at Amazon.
One of the best fleece products that we use on the river and on the ski hill is the Cletus Hood from Knucklehead Threads.
This oversized fleece hood comes detached from a jacket and can be worn as a hat or over your rafting or skiing helmet.
When running whitewater in the winter, we always wear our Cletus hoods over our helmets. And when we’re storm skiing through powder, we slip the hood over our ski helmets because it stays warm even after getting wet from the snow.
At only $35, the Cletus Hood is a piece of rafting and skiing gear you can’t go wrong owning!
The beauty of fleece clothing is that expensive and less expensive polyester fleece clothing seems to perform equally when wet.
Learn more about the essential clothing for rafting.
Why Is It Important to Stay Warm When Rafting?
We’ve seen it a million times—some tough-guy dude-bro first-time rafter who isn’t scared of getting wet and cold gets on your boat.
You tell him, “While I know it’s 80 degrees out, and you’re SUPER tough, please put on this fleece under your splash top.” He refuses and then shivers all the way down the river, paddling at half capacity.
It doesn’t matter how tough you are or how resilient you are to cold weather. There will always be a moment when the human body becomes too cold to remain healthy and too cold to be a good rafting partner.
When you get too cold, your brain and body cannot function. End of story.
When rafting, all members must be willing and able to paddle, row, and perform rescue functions for themselves or others.
That’s why it is crucial to wear the appropriate clothing when rafting.
Best Fleece Clothing for Staying Warm When Wet
Here is our list of the best fleece clothing for rafting and outdoor activities where staying warm is crucial.
Each piece of clothing recommended is made from synthetic polyester fleece, which is designed to keep you warm when wet.
Immersion Research Thick Skin Fleece Union Body Suit
This offering from Immersion Research is a full-body fleece base (or mid) layer designed to be worn under a dry suit. It is a one-piece layering system for rafting or paddling in the coldest conditions. It is offered in Men’s and Women’s sizes. The women’s version includes a full drop seat relief zipper, allowing you to pee without removing the whole layer. Even though a dry suit is designed to keep you completely dry, it’s nice to have a good insulating layer under the dry suit that will retain warmth in the event the dry suit fails.
NRS Expedition Weight Shirt
We like this as a mid-layer under your splash jacket, dry top, or dry suit. This hoodless piece is simple, durable, and keeps you warm when running rapids. It is stylish and versatile enough to wear around the campfire or as a layering piece for other outdoor sports like fly fishing or hiking. The Expedition Weight Shirt comes in men’s and women’s sizes.
NRS Lightweight Pant
Similar to the expedition weight shirt, these bottoms are cotton-free and guaranteed to help keep you warm when wet. We like the lightweight version of these pants because they are more versatile for high-output activities than heavier garments. These fleece pants come in men’s and women’s sizes.
Under Amour Men‘s Fleece Pullover
You don’t have to spend over $100 to get a good fleece layer. This fleece pullover from Under Armour won’t break the bank (at around $40) and will help keep you warm, even when soaking wet. This pullover is offered in men’s sizes only.
Columbia Women’s Glacial Iv Half Zip
This is a very comfortable pullover fleece top for women. It is made from 100% polyester, meaning it will retain warmth when wet, similar to wool clothing.
Knucklehead Cletus Hood
This is an oversized stand-alone helmet-compatible fleece hood that everyone should own! We love it because it is comfortable, affordable, stylish, and can be worn over a helmet or not. The Cletus is hand-made in Crested Butte, Colorado.
Conclusion
When we’re on the river, it’s possible to fall in at any time, resulting in a dangerous outcome. That’s why it’s essential never to wear cotton when rafting; instead, wear wool or fleece base/mid-layers.
Wool and fleece both have excellent insulating properties and are among the best materials for providing warmth even when wet.
Splash or dry gear is also recommended for most rafting adventures, as is a well-maintained PFD and helmet. For more information about what to wear when rafting or details on how to care for your PFD in the Slackwater blog.
Thanks for reading.