Cold Water Swimming,  EXTRA,  GEAR,  Gear Advice,  January 2024,  Product Reviews

How to layer up after a cold swim

With numb fingers, damp skin and scant shelter, it can be hard to get dressed and warm after a cold water dip. Understanding the benefits of layers and the right materials can make all the difference

How to create a layering system 

One of the most efficient ways to warm up after a swim is to layer two or three insulating garments, rather than throwing on a big jumper. That’s because layers help to move moisture away from your skin and trap heat close to the body. Ronnie Legg, head of clothing design at Alpkit, explains the benefits of a basic layering system: “The base layer moves moisture away from your skin, keeping you dry from the inside out. A mid-layer (something with a little extra bulk such as recycled fleece, heavier-weight merino wool or an insulating body warmer) traps warm air near your body, keeping you warm from the outside in. Lastly, the outer layer prevents wind and rain stealing that warm air from you.” Lastly, don’t neglect your extremities! Add extra warmth with thick socks, a woolly bobble hat, scarf and gloves. And bear in mind that when you exit the water, your core continues to cool down for the next 10 to 40 minutes so you need to get those layers on quickly to help raise and regulate your core temperature.

Why material matters

When it comes to staying warm, material matters. The main issue is moisture management. “If your skin is wet you will feel cold, so you want a fabric that can pick moisture up and move it away from your skin (so called ‘wicking’),” says Ronnie. While cotton is good at absorbing water, it’s not very good at letting go of it again and if your clothes stay wet, you’ll get cold. Merino wool is actually similar in that it absorbs moisture, however when it dries it releases warmth.

“The hardy sheep that produce merino live in environments with extreme weather conditions, which has led their fleeces to evolve some incredible features”, says Alex Feechan, founder of sustainable outdoor clothing brand Findra. “Merino wool fibres also have a natural temperature regulation and odour resistance that ensure the sheep’s survival.” Merino is also biodegradable and can be composted or recycled at the end of its life, and it doesn’t shed plastic microfibres when you wash it either. 

When one layer is enough

While layering is an efficient way to conserve body heat, a few garments combine the benefits of a ‘layering system’ into a single minimal layer, made to be worn next to your skin. The Buffalo Mountain Shirt, Alpkit Jura Mountain Smock and innovative Wylding boiler suit feature hydrophobic fleece lining that’s fast-wicking and insulating even when damp. “If your swim isn’t that far from your start point, then a full blown layering system may not be worth the time to put it all on,” says Ronnie. Garments like these come at a price, but when you consider that an all-in-one system replaces the need for several layers, and how they can be used in a range of situations, their cost-per-wear begins to make sense. 

More tips for keeping warm

All swimmers have their tips and tricks for warming up. Gear editor Jo Tinsley recommends changing into an unworn base layer rather than the top you’ve been sweating into all day. Even though wool retains insulating properties when wet, putting on damp layers will sap your body heat. You can also warm your core from the inside-out by sipping tea or hot chocolate; Simon Griffiths swears by sweet milky chai followed by hot porridge once home. Finally, move your body! “Remember that a clothing system can only trap your body warmth and prevent you from cooling down more, it can’t actively warm you up,” says Ronnie. Generate heat by stamping your feet, walking or stretching to improve circulation and gradually raise your body temperature.


Alpkit Kepler Vest and Boxers

Vest £44.99, Boxers £29.99

They say: A lightweight merino base layer is a staple piece of most peoples’ layering systems. This 100% pure merino wool vest is breathable, wicking, fast drying and odour resistant, while the matching merino undercrackers keep your bum comfy with Corespun fabric for a longer life and lasting fit. (Women’s boxers size 6-20; vest 8-18; men’s boxers 28”-38”).

We say: This versatile vest is a great next-to-the-skin layer, which keeps you warm in winter and regulates your temperature in summer. Soft to the touch, it machine washes well at 30ºC (just don’t tumble it). It even works on damp post-swim skin, drawing water away so it can evaporate. OK so merino boxers are a bit of a luxury, but there’s no point kitting up in technical gear if your cotton undies are going to get all clammy, right?


Smartwool Classic Thermal Merino Base Layer Crew

£99.99

They say: We’ve updated this 100% merino wool, fan favourite with new colour options and an enhanced fit to improve functionality. The addition of shoulder panels and flatlock seam construction help prevent chafing. (Size Xs-XL).

We say: This felt luxury from the moment we put it on. Super supportive, yet comfortable. One night, after a particularly cold swim, we even slept in it! The slim fit ensures a close skin warmth, while making it easy to layer-up. We love the colour range too, from neutral to bright. The fabric is soft and not itchy, 100% wool means it won’t stink, and it’s great if you’re still a bit damp after swimming. Plus-point – saving on heating when working from home by wearing it while we work.


Findra Elsie hoodie

£105

They say: Made in the UK with zero waste, the Elsie hoodie is made from 100% ultra-soft Australian merino wool, nature’s own technical fabric. Merino wool is breathable, fast-drying and wicks moisture away from the skin, regulating your core body temperature. Lightweight, casual, comfortable and stylish, the Elsie is a perfect all year-round sweater that easily transitions from season to season. (Size 8-18).

We say: We’ve barely taken this hoodie off and barely had to wash it either, thanks to the merino wool’s odour-resistant and anti-bacterial qualities. As a mid-weight layer, it provides superb insulation after a cold-water swim, under a jumper or changing robe. It kept us warm, and the merino felt super-soft against sensitive, goose-bumped skin. This hoodie is also a staple for everyday wear, the thumbholes ensure the sleeves don’t rise up so wrists stay warm while working.


Howies Women’s Furzenip Merino Leggings

£79

They say: Insulating leggings made from 100% merino wool in a soft jacquard knit. Designed to give you an extra layer of warmth during the colder months, these are super soft and itch-free – they feel great next to your skin. Featuring an all-over pattern based on traditional Welsh tapestry blankets. (Size 8-16).

We say: We absolutely loved these merino leggings, which at 240gsm are heavier weight than a standard base layer fabric. In autumn, we wore them as a single layer – the gorgeous Welsh tapestry pattern isn’t the slightest bit transparent. In winter, we layered them under jeans. They wash well at 30ºC and dry naturally relatively quickly. We also liked the coordinating Women’s Linney Long Sleeved Merino Top (£79, reviewed online), with its cosy funnel collar, deep cuffs and thumb holes.


Selkie Swim Co Unisex Body Warmer

£60 (£30 discounted offer)

They say: This gilet is the ideal layering piece for autumn; its lightweight polyester fill will keep you super warm. It is filled with effective synthetic insulation (#nofeathers) providing warmth like down but surpassing its quality in terms of durability and water resistance. It has a zip closure and zipped front pockets with fleece lining to keep the heat in. (Chest 32”-45”).

We say: This was a piece of kit we thought unnecessary, until we tried it. Now it comes along for every swim. After a winter dip, it’s a luxury extra layer that goes on under a jacket or robe and doesn’t feel restrictive around the shoulders like an extra jumper might do. Come warmer weather, it’s a lightweight layer ready to pull on if there’s a sudden drop in temperature. The only puzzle are the two internal pouches that look like pockets, but aren’t.


Wylding suit

£160

They say: The Wylding suit is a relaxed fit, thermal lined, weatherproof boiler suit. It is designed to be worn with only underwear or dry swimwear underneath, allowing the wearer to move unencumbered while staying warm. The technical properties of the fabric, along with the considered silhouette, makes the transition into and out of cold water fast, effortless and stylish for all blue health seekers.

We say: It’s hard to emphasise just how much we loved this suit. The drop crotch and roomy size made for effortless post-swim changes and the thermal fleece dealt with any residual skin dampness, while the tailored silhouette made it feel smart enough to head to the pub after a dip. The simplicity of being able to wear it over underwear meant we could get on with warming up with a hot drink while others were still wrestling with their layers. 


UZE Graphene Heated Jacket

$599 ($299 discounted offer)

They say: A groundbreaking creation that combines the extraordinary thermal properties of graphene with a sophisticated design. Central to the UZE Heated Jacket is its cutting-edge graphene heating pads. These pads are renowned for their exceptional heat-conducting capabilities, warming up three times quicker than traditional alternatives and achieving temperatures of up to 70°C.  (Size XS-XXL).

We say: This sounded a bit too good to be true, but what a great product! The heated pads make a real difference – no more hot water bottles stuck inside a coat! – but what we loved the most was the versatility of the jacket, which can be worn in all seasons. Every detail is brilliant, from adjustable cuffs and fingerless gloves to the detachable inside for warmer months. The heat pads on the back are amazing after a dip. 


Swimbler Night Sky Navy Grey Waterproof Bobble Hat

£32

They say: This lovely warm pom pom hat is made with three layers, with a soft warm fleece lining and a second layer of eco stormactive membrane below the acrylic yarn and huge 15cm detachable pom pom. Possibly the warmest hat you will own, it keeps the wind chill and the elements off your head too. (One size).

We say: One of the best parts of this feature has been reviewing kit (like this bobble hat, made by winter swimmer Lisa Thomas) that’s been designed by outdoor swimmers, as who knows our needs better than someone who regularly dunks in cold water? This warm hat is weatherproof, the acrylic outer and waterproof membrane keep off the wind and rain, while the fleece lining feels soft and warm. An enormous detachable (and interchangeable) pom pom adds extra fun.


Ghost Robes Speed Socks

£30

They say: Luxury merino-mix socks designed for outdoor swimmers to wear before and after swimming. They have been designed to easily slide onto damp feet when your hands are not functioning as well as you would like them to. Speed Socks are made in Yorkshire, using traditional methods combined with modern machinery, ensuring the highest quality for your feet and sustainability for the environment. (Size 3-11).

We say: Fumbling to get socks on cold feet when you have numb fingers is one of the real bugbears of winter swimming. These long and thick merino-mix socks are so easy to pull on and feel so soft and warm. Made from 74% merino, you don’t even have to wash them after each wear; simply leave them to air overnight. The nylon mix adds strength and durability.


Arctic Fox & Co Recycled Bottle Gloves

£22

They say: Crafted from recycled plastic bottles, not only are you supporting a greener planet, but you’re also ensuring your hands stay cosy after those invigorating winter swims. Designed with a snug ribbed construction, these gloves lock in warmth efficiently, ensuring that your focus remains on your swim, and not the cold. They also come with integrated touch screen technology, making it easy for you to capture those breathtaking open water moments without having to remove them. 

We say: Close fitting and made with a fine ribbed knit, these gloves were much warmer than they first appeared and kept our hands cosy before and after swims – cosier, in fact, than the much thicker, woolly gloves we usually wear. On an iPhone, the black touch screen tips were hit and miss, but that didn’t put us off as they were nimble enough that we could fasten zips and buttons, dig out car keys and find change for a warming drink without having to ever take them off!

Compiled with help from the experts at Alpkit and Findra. If you buy a product through a link on this page we may receive a commission.

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Jo is the Gear Editor for Outdoor Swimmer and also writes news and features for the website. A keen open water swimmer and long-distance walker, she loves seeking out lakes and lidos close to her home in the Mendip Hills, Somerset. She is the author of The Slow Traveller, editor and founder of independent magazine, Ernest, and has previously tested outdoor clothing and kit for BBC Countryfile Magazine, BBC Focus and Ernest Journal.