While the UK’s weather has always been variable enough to keep things interesting, the highs and lows are now less predictable than ever. Whether dressing yourself or your kids, it’s hard to know at this time of year whether you can expect a biting chill or unseasonal sunshine.
The solution as we approach winter, of course, is to start with a thermal base and add layers on top, keeping warm air close to your body but allowing you to adjust as necessary. Beware: with the wrong pieces, this can be cumbersome and sweaty. So how do we do it, and is it too much to hope that we could also look good?
Thankfully, it’s not, because thermals have come a very long way. Over two decades and counting, Uniqlo has put a huge amount of research into its famous HEATTECH range, developing 10,000 fabric prototypes along the way. Four kinds of fibre are used across the range, to variously trap air, retain heat, provide stretch and absorb moisture. Though the clothes remain very affordable, these hi-tech fabrics ensure that nothing is offputtingly thick or uncomfortable.
This “innerwear” – as the brand calls it – looks nothing like underwear, which is good news when you walk into a warm restaurant or office and have to immediately strip down to your base layer. Uniqlo’s creative director is Clare Waight Keller, previously of Givenchy and Chloé; the Tokyo-based brand has a pleasingly clean, timeless aesthetic and a neutral colour palette designed to suit all skin tones. These are not your grandparents’ thermals, and if it’s not quite cold enough to wear a jumper and a coat on top, they’ll look great under an open shirt or jacket.
The range’s crew-neck, long-sleeved T-shirt – available in both women’s and men’s sizing – is for many people the go-to foundation of a winter outfit. It’s made of a stretch fabric that’s fine enough to be worn under a sweater. The brand offers variations in style and sleeve-length too, including a scoop-neck version for women and kids, and a short-sleeved V-neck for men.
There are also warmer options, such as the women’s cashmere-blend, long-sleeved T-shirt from the brand’s Uniqlo: C HEATTECH range (also available in a turtleneck for him or her). The cashmere yarns are approximately half the thickness of those used in sweaters, leaving the T-shirts slightly sheer – and rather chic. The brand has developed a special dyeing machine that reduces load on the fabric as much as possible, keeping it a little fluffier than your average thermals. (For seriously cold conditions, you’ll want Uniqlo’s ultra warm range, which is knitted to create air pockets for extra heat retention – very good for snowy holidays.)
Each of these pieces is neutral enough to be paired with almost anything and styled in your own way. You could layer a standard cotton T-shirt over a HEATTECH one with a longer sleeve-length, and wear it simply with jeans for the weekend. A loose v-neck jumper will look great over a contrasting crew-neck tee – or you can dress up your thermal by tucking it into a skirt or tailored trousers, and layering a longer jacket or blazer over the top.
As the weather gets colder, you’ll want a pair of Uniqlo HEATTECH tights in your armory. They’re opaque and won’t draw attention, but their secret superpower is in being far cosier than normal hosiery. In the depths of January you’ll be very happy to pull on some from the ultra warm range, which retain even more heat and are lined with a comfortingly fleecy pile.
For men, the must-have in the HEATTECH range might be the easy trousers, which come in longer or shorter versions and are made of a water-repellent fabric with two-way stretch. With a classic, tapered shape, they don’t look like they’re designed to withstand iffy weather – but they are.
Clever layering really comes into its own with children, since coats are inevitably discarded in the playground and thick clothes can restrict play. The kids’ HEATTECH range contains soft cotton, with special care being taken on the seams to avoid the kind of itchy threads that can drive a child to distraction. The fabric also has stretch – useful on a climbing frame – and Uniqlo has shrewdly increased the durability of the collars.
The scoop-necked, long-sleeved HEATTECH T-shirt and stretchy black leggings are unisex and available for ages three to 13. Kids will love the glitter tights – which are still thermal and, importantly, designed with a waistband that won’t twist during play.
While all this tech is rather impressive, the clothes themselves are designed in a whisper, not a shout. They simply work, so that you hardly have to think about them at all.
When Uniqlo launched its Heart of Lifewear initiative to mark the brand’s 40th anniversary in 2024, it donated more than one million items of HEATTECH thermal clothing to refugees, children, disaster victims, and other people in difficult situations around the world to make their lives a little more comfortable. Uniqlo has followed it up this year with the same commitment and by the end of 2025 will have donated an additional one million more items to vulnerable people globally, with around half of this assistance going to refugees returning to Syria.
Style it out – and stay cosy. Shop the Uniqlo HEATTECH collection
