The Gear Shed - Layering for Cold Weather
Layering is a great way to stay warm and comfortable while enjoying the outdoors. It’s especially useful if you plan on spending time outside in colder temperatures. You want to make sure you layer correctly so you don’t get too hot or too cold. Here are some tips to help you do just that.
Why is Layering Important?
The main goal of layering is to prevent:
Cold Shock
Hypothermia
Heat Related Illnesses
Cold shock is a physiological response to sudden cold-water immersion which can affect body movement, cognition, and respiration. Cold shock often results from immersion in icy or cold water.
Hypothermia is a condition where your body loses more heat than it can produce. Normally, hypothermia sets in when a patient’s body temperature nears 95 degrees Fahrenheit. As with cold shock, hypothermia can affect both body movement and cognitive abilities. For dry gear, hypothermia typically results from moisture retention within your dry suit.
Heat stroke and heat exhaustion can arise from excessive heat retention. Without proper layering, you won’t be able to adapt to changing conditions, or remove insulation to prevent heat stroke.
A couple more important terms to understand throughout this article are hydrophobic and hydrophilic. Hydrophobic refers to a materials tendency not to absorb water. Hydrophilic refers to a materials tendency to absorb water and this can be very detrimental in the outdoors.
As with all layering strategies, the goal is to maximize flexibility and adaptability. Below is the system we use when heading out into the outdoors during cold weather.
Outdoor Layering Systems
Lightweight Wicking layer
Midweight Layer
Primary Insulating Layer
Secondary Insulating Layer
Outer Shell Layer
These layers can be mixed and matched to create insulation systems that, once you become familiar with them, are customizable to any condition. The good news though is that regardless of your outdoor sport of choice these principles are the same and you can use all of the same base layers to stay warm and have fun out there.
For boaters, we actively seek out water and immersion, whereas other athletes try to avoid it. Because of that, we must carefully evaluate our layering system. For example, our outer shell layers are a double-edged sword since they are usually not breathable due to their waterproofness.
Lightweight Wicking Layer
Purpose – Wick moisture away from skin and regulate body temperature
Recommended Materials – Polyester and Polypropylene
Lightweight base layers are designed to draw moisture away from skin, and to regulate body heat. This may consist of a short sleeve shirt and shorts but generally you want to have long light weight layers to help efficiently deal with sweat. For colder days, it is best to use lightweight long underwear. For most outdoor activities, but especially paddle sports you want to make sure you do not have bear skin contacting your outer layer. Not only will it be cold, but your skin oils can damage materials like ePTFE or Gore-Tex as it is more commonly known.
Mid-weight layer
Purpose – Wick moisture away from skin, prevent chafing, and the first insulating layer
Recommended Materials – Polyester
Mid-weight base layers also wick moisture away from the skin and regulate temperature like lightweight layers. These layers can also be used as your last layer before your outer layer for moderate insulation on warmer days. Because these layers promote wicking, we recommend hydrophobic fabrics. This layer also protects your skin from chafing under your outer layer.
Primary Insulating layer
Purpose – Trap heat and maintain core temperature
Recommended Materials – Microfleece, wool, or down-like insulation
Insulating layers are designed to retain heat by preventing conduction. If you only have one insulating layer, fleece works best. Fleece works well here, but down is also a good choice for general outdoor activity. For rafting and kayaking you want to make sure you are not wearing hydrophilic layers like wool or down unless you are in a full drysuit that you know is watertight.
Secondary Insulating Layer
Purpose – Increase heat retention in extreme cold
Recommended Materials – Microfleece, Wool
If you are out during extremely cold days, considering using a secondary long insulating layer like micro-fleece keep your core warm. This provides an additional barrier between the cold-outer layer and your body further preventing heat loss through conduction.
Outer Layer
Hard shell layer – Moisture Impermeability
Recommended Materials – Nylon or Polyester sandwiching an ePTFE / Gore-Tex Membrane
This layer is your impermeable hard outer shell layer. Outer hard-shell layers are typically made from Nylon or Polyester or closely related polymers to these materials. Outer shells are highly effective against wind and prevents heat loss via convection between your body and cold air, rain, snow, or water.
For paddle sports, this layer is your drysuit or dry-top / paddle pant combination. This layer provides an impermeable barrier to seal out water. If you want to learn more about drysuits you can find out more here.
Socks and Footwear
Proper layering of socks and footwear are essential to having a good experience in the outdoors. Cold or wet feet can ruin almost any outdoor adventure. If feet are cold and wet long enough you can even develop several medical conditions that will quickly end your outing. Oddly enough, thin polyester dress socks are a highly effective and economical option for base layers to wick sweat away. Thick wool or synthetic socks are your best option for insulating layers footwear. In most sports you will be wearing some sort of shoe after your insulating layer and 1 pair of good wicking socks may be appropriate.
Paddle sports are a bit of an oddity since you typically want 2 layers of socks and they are usually covered by drysuit booties creating a water tight outer layer. Unfortunately, drysuit booties are the most likely failure point and quickest to wear part of the suit to wear out. Many boaters joke that they are only good for 4 trips then they have holes. You can help this situation though by selecting shoes that are both insulating and have higher tops to help seal out debris. Most high top drysuit shoes also contain an insulating layer like neoprene which can help keep your feet warmer. If you want to learn more about proper rafting or kayaking footwear you can find out more info here.
Gloves and Hats
Your head and hands are most likely to be affected by cold weather first so it is important to make sure you are taking care of them by following a similar layering system to the rest of your body. Having a wicking layer on your hands followed by an insulating outer shell is critical. In all cases mittens are more efficient at insulating your fingers, however they come at the price of limiting mobility. If you are in paddle sports the standard option for gloves may not work so going with a neoprene glove can help keep your hands warm.
On your head, you can use a wicking skull cap or balaclava under your helmet to increase insulation and heat retention. This generally works in all sports, but somewhat less efficiently in paddle sports since you are constantly wet. Similarly, to gloves you can use a neoprene hood to keep your head warm if your helmet is not enough.
Material Guide
Outer Layer Materials
Polyester – Polyester outer layers are hydrophobic and resist water absorption. Polyester is also resistant to UV damage, making it a great option for cold rivers with clear skies. One downside is that polyester is typically less abrasion-resistant than Nylon. You can learn more about Polyester here.
Nylon – Although nylon is like polyester in many ways, the key difference is that Nylon is naturally hydrophilic and absorbs water. By absorbing water, nylon outer layers can often “wet out” or allow natural conduction between body heat and water. Nylon outer layers also take longer to dry than polyester. Ultimately, Nylon outer layers are better for day trips or brushy condition where hiking, climbing, or portaging is likely because Nylon is more abrasion resistant than Polyester. You can learn more about Nylon here.
Insulation Materials
Fleece (microfleece) – A wet boater’s best friend. Fleece is naturally hydrophobic due to the manufacturing process, and will absorb less than .01% of its weight in water. It is an extremely powerful insulator.
Wool – For dry suit layering, wool is a great choice and excellent insulator. One potential issue is that wool is more hydrophilic than polyester microfleece and more likely to absorb sweat. This is also not a good choice for semi-dry gear because it can quickly become waterlogged and cause you to lose body heat. We like that the material is more environmentally friendly and doesn’t release micro-plastics when washed.
Down – Insulating down may seem like an odd choice for the water, but advances in environmentally-friendly feather coatings have improved its ability to retain heat and go longer before wetting out.
Wicking Materials
Polyester – Polyester under layers have excellent moisture wicking properties. Just be sure of the composition of the layer because many manufacturers use blends of Polyester with Cotton, Lycra, and Spandex.
Polypropylene & Capilene – Many boaters prefer polypropylene and Capilene, over the materials above because they offer slightly better heat retention properties than other base layer materials like polyester.
Bad Layering Practices
Cotton – Nope, just Nope! Boaters should actively avoid cotton fabrics while on the water. Cotton is non-wicking and keeps moisture close to the skin. In Winter months, this could rapidly induce hypothermia.
Neoprene / Hydroskin – Neoprene is an insulating material designed to keep a thin layer of warm water against your body. Because of that, it is not a good option for wearing under your dry-suit. It is not a breathable material since it has a completely different usage in mind. Avoid any of this type of material including a neoprene blend. The only exception being Neoprene booties over your drysuit are ok.
Lycra and Spandex - Lycra and Spandex are poor materials for heat retention since stretchy materials tend to trap water between the fibers. One consideration for female boaters is that form fitting and supporting Lycra or Spandex garments are slow to dry. These materials are hydrophilic and slow to dry creating a serious risk of skin irritation, rash, and infection because of bacterial growth.
Layering Best Practices for Boaters
Unlike many other adventure sports you will always be wearing your outer layer and generally you should always wear your lightweight layer (to avoid chafing). The question is how many more layers should you wear? When layering for dry gear, the most important factor is if you will be wearing a full dry suit or a dry top and paddle pants. The next important factor to consider is expected precipitation, wind chill, air and water temperature. Personal preference is also a factor since some people run hotter or colder.
Follow weather forecasts, and conservatively plan your layering for the felt air temperature, which can be determined by comparing the lowest predicted air temperature and expected wind speed. If the water temperature is lower than the estimated felt air temperature, plan for that.
If it is raining, add one additional layer to account for heat loss. For example, if it is a warmer day and you planned on wearing only base layers, add an insulating layer when it rains.
Wait until your raft is rigged and inflated before donning your dry suit. This will give you time to cool down and not trap sweat inside the dry suit.
Bring a dry bag so that you can add or drop layers as conditions require. Having an extra insulating layer in your dry bag will also allow you to adapt to unexpected conditions.
Because dry tops and paddle pant combinations are more prone to leaking, avoid down or wool insulation.
Avoid using moisture absorbing powders because they can increase moisture retention in key areas and quickly drain body heat.
Precipitation
Precipitation, like rain or snow, presents a unique consideration for dry-suit wearing rafters. Unlike whitewater kayakers, rafters do not typically get drenched by each small and medium wave. Because of that, it may be difficult to vent excess heat on days with no precipitation. On trips with rain or snow, the precipitation will continuously drain heat from your dry-suit and body through convection cooling. You may feel warm at the put-in, but precipitation will rapidly lower the temperature of your outer layers. Therefore, if you expect rain or snow, wear heavier insulation than on cold-clear days.
Wind Chill and Air Temperature
Ambient air temperature, cloud cover, and wind speed should also factor into your layering strategy. If there will be no direct sunlight, you will probably want to include an extra layer. The same goes for wind speed, where high winds can rapidly drain body heat. It is important to understand wind chill if you spend time outdoors. Wind chill is a measure of the convective effect of air on your body temperature. To better understand wind chill, the National Oceanic and Atmospheric Administration (NOAA) offers a helpful online calculator. Based on actual temperature and wind speed, their calculator will determine the felt-temperature. For example, if the actual temperature was 40 degrees Fahrenheit with a wind speed of 11 m.p.h., your body will feel and lose heat as if it were 33 degrees Fahrenheit.
Water Temperature
For rafters, the most powerful heat dissipating force will be water. Depending on local conditions during winter months, river water may actually be warmer than ambient air temperature, especially if it is below freezing outside the water. Most modern river gauges have thermometers built into them, but we recommend carrying a thermometer in your shuttle vehicle. This allows you to check the water temperature at the put-in and reminds you to take extra precautions.
Dry Top / Paddle Pants Combination
For this combination, there two points for potential failure:
Waist Band – This is the most likely point of failure for dry tops or paddle pants. If the waist band is loose or moves significantly, you will experience leakage. It is important for the waist band of dry tops or paddle pants to remain secure and close to the body to avoid water intrusion.
Ankles – If your paddle pants include integrated fabric or latex booties, this can present a serious hazard if your waistband fails and the pants fill with water. For that reason, its best to keep a sharp knife on hand. At the same time, if your paddle pants do not include integrated booties, make sure to wear extra layers of footwear. Neoprene booties can become very cold on long days, quickly draining body heat.
