'Denim is rubbish for keeping you warm': experts' tips for cold-weather dressing

Spending time outdoors was fine in June when it might have involved beer, picnic dressing and socially distanced picnic rugs in the local park. And the outdoors remains vital to life right now, whether that is for a sanity-restoring walk or – depending on where you are in the UK – a meet-up with five friends. But when the temperature is somewhere between 7C and 14C, it takes on a different complexion. Taking rambler Arthur Wainwright’s memorable adage that there is no bad weather, only bad clothes, we asked a groundsman, a dog-walker, a professional snowboarder, a National Trust ranger and others what to wear to keep the heat in and the cold out.

Should you invest in thermals?

Probably. Jenny Jones, an Olympic snowboarder, says: “Your base layer is key because you want something that’s close to your body that’s going to keep the warmth in. It’s all about keeping the middle part of your body [warm], where all your vital organs are.” Adrian Bruton has been a groundsman everywhere from Arsenal’s training ground to Brighton college. He says the thermal tops that adapt to your temperature are the best. “Under Armour is really good. When you’re outside in the cold it keeps you warm and when you go indoors into a cooler environment, it almost feels cool on your skin.” Avoid cotton, says Catherine Hadler, a National Trust ranger: “You sweat [when you walk] and that will then chill when you stop. Most thermals are designed so that if you do get hot and sweat, it will kind of wick it away instead of it just sitting there and chilling you.”

Do you need to rethink your hat?

Not really. While it’s not entirely true that we lose most of our heat from our heads, all our experts agree that hat-wearing is a good idea, and they are especially enthusiastic about cosy ones. Jones and Bruton mention the importance of covering your ears – Bruton prefers a deerstalker type – but knitting could become a new valued skill, with the woolly beanie name-checked as an essential accessory. “I’m all for a woolly hat in winter,” says Hadler. “My mum knits me lots, and I have every colour.” They can be worn everywhere, too. Felicity Moir, an acupuncturist who swims every day at the Hampstead ponds in north London, says: “A lot of people swim with a woolly hat on. It’s a very funny sight.”

How important is your coat?

Once your base layer is sorted, turn your attention to your top layer, and find the coat to take you out in all weathers. Louise Kyei-Balffour, who runs the north-London dog-walking service, Pups Go Walking, swears by a faux sheepskin fabric coat her mum made, combined with just a jumper. Jones says she would recommend a padded jacket. “I would wear one of those thicker jackets. If you’re standing still, you’ve got [to make sure] your core sorted out.” Bruton, in the same vein, recommends a body warmer or gilet, “because they’re comfortable, you don’t feel too enclosed. We get them from Dickies and places like that”.

Alternatively, Lasse Heimdal, the general secretary of Norsk Friluftsliv, AKA the Norwegian Association for Outdoor Organisations, recommends a jacket with ventilation, so you don’t overheat while walking. He sounds a note of caution, however. “If you use a shell jacket like the one I have, they keep you dry, but they don’t keep you warm, so it’s very important to have a sweater under it,” he says. “Because some people misunderstand the use of this jacket. You can really freeze in this jacket if you don’t have a good sweater under it.”

What’s the best way to keep your hands warm?

There’s a bit of disagreement here. Jones says: “I am all about mittens … when you’re in the mountains, and you’re sitting on chairlifts, you just don’t want your hands exposed. You can also wear thin gloves underneath if you want extra warmth.” Hadler is keen on “waterproof gloves that are quite flexible. So I can still work with them.” She also recommends “little reusable handwarmers. You click them and you can have them in your pocket and then when they have cooled down, you just boil them in a pan of water to reset them.”

Should you wear a scarf?

A neck warmer is more the thing, to avoid any wind getting to your skin. “I wear a neck buff, a bit like a snood. Lots of people have the colourful thin ones to wear on hikes and things, but I get a slightly fleecy one for winter,” says Hadler. “I sound like I hate the wind, but I’m obsessed because the wind makes you so cold.”

Where are we at with socks?

While Moir is hardy, changing into only cotton socks after her swim whatever the weather, merino wool socks are recommended for warmth. Layering is an option. “You can get a thin base-layer walking sock then a thicker one to go over the top in wellies, that’s quite good,” says Hadler. Jones warns against going too thick because, “if you are wearing thick socks but your shoes are very tight, that can cause your feet to be colder. The gap is what insulates you – that bit of trapped air.” Alternatively, go with Kyei-Balffour’s feet warmers. “They’re little heat packs … you stick one in your boot and it lasts for up to eight hours. I feel like it’s just right because sometimes you get really thick socks, and that can suffocate you. So you can put thin socks [and the warmers], and that feels just right.”

What should you avoid?

Even on dry days, Hadler says jeans are not your friend. “I sound like my Duke of Edinburgh’s award leader, but denim is rubbish for keeping you warm,” she says. “You could go out in some thicker leggings and a long woolly jumper and you’ll probably be warmer if you’re sitting in a friend’s garden.”

Is it all about technical fabrics?

Not according to Heimdal. He’s a big fan of wool, particularly under the shell jacket he recommends. “When you’re doing the outdoor life, we will seldom use cotton materials because, when they get wet, either by rain or sweating, you can get really cold,” he says. “It can get wet, but it won’t get cold. It has the ability to keep you warm even though you are wet inside so that’s very important.”

Are there any less-well-known warming hacks you could try?

Bruton says on freezing days, “when we’re sitting on tractors and stuff, a lined onesie keeps you warm. You can buy ones that are windproof, element-proof, rainproof.” Hadler describes a heated waistcoat as “a game-changer”. “I got it from Amazon, and it’s rechargeable,” she says. “I put it on either if I’m out or if I’m in a workshop. It has got a heat pad round the back where your kidneys are.” Moir says she has experimented with taking a hot-water bottle swimming. “I wrapped it up in my towel so that my towel was warm and then I’d just stick it down my jumper,” she says. Heimdal emphasises the importance of bringing “rewards” on a walk, such as raisins, chocolate and a ovacuum flask of coffee. “The main thing for a successful trip out is to keep warm and dry,” he says. “And have a good time.”