Best thermal clothing for keeping warm this winter

Let’s get one thing straight: we all sweat, especially during intense periods of exercise, whether it’s hiking, skiing or cycling. But we don’t necessarily want to smell like we do, which is why we’re especially impressed with Patagonia’s leggings, which rely on an odour-controlling biocide (a chemical substance, in a nutshell) to control nasty niffs. No matter how, where or when you’re working up a sweat, these bad boys will keep odour to a minimum.

But that’s not the only reason we love these thermal leggings, which use hollow-core yarns to trap warm air, while the lightweight, sweat-wicking material ramps up the comfort, and flatlock seams minimise the risk of chafing. We’re also impressed with the sustainability – the packaging consisted entirely of cardboard, and the leggings are Fairtrade-certified.

These are some of the softest thermal leggings we’ve come across – largely thanks to their fleece-like inner lining. This pair is another example of a thermal garment packed with tech. The stars of the show include the NILIT heat yarn technology, which provides unbeatable sweat-wicking, temperature regulation (fun fact: it’s made partly with coffee charcoal waste from coffee bean shells) and precision-engineered knitted panels. We loved the high waistband, as well as the material’s incredible lightness, which meant we were perfectly happy to wear these around the house, too.

Musto, a brand loved by seafarers, is known for producing highly technical garments that are built to last. This top is no exception, combining unbeatable temperature regulation with style, thanks to a flattering fit and a jaunty red trim down the side. But there’s plenty of substance here, too. A precision-engineered combination of polyester, polyamide and elastane provides brilliant sweat-wicking, and means this garment dries incredibly quickly.

Technical features worth highlighting include the twin needle stitch hem and cuffs (referring to a double row of stitches designed to provide extra stretch) and the raglan-style sleeves (made from continuous pieces of material that extend to the collar), which offer additional freedom of movement. We also loved the funnel neck, which helped us retain heat in cooler climes, while keeping us warm and dry.

This is a brilliant example of a thermal garment that is a million miles away from the thermal clothing of yesteryear. It’s wonderfully soft and has an on-trend design, which means this is a garment you’ll be proud to be seen in – it will take you effortlessly from the ski run to the slope-side bar. In this case, the top’s thermal qualities come from the cable knit design, along with the generously sized hood.

Cold-weather clothing can be hard to get right, but 66 North has knocked it out of the ballpark with their power stretch pro pants, which feel wonderfully soft – more like our favourite slouchy joggers than thermals – and kept us toasty warm (largely thanks to their dual-surface knit construction) on an incredibly chilly day.

They’re fabulously versatile and can easily be worn under trousers when the mercury’s plummeted, but we’d also be perfectly happy wearing these at home on days when we simply can’t be bothered to crank up the radiator. A heavy reliance on polartec pro material – known for its sweat-wicking capabilities, its four-way stretch courtesy of reinforced elastic fibres, and its ability to retain shape, wash after wash – results in a fantastic garment that offers both durability and style.

Another wonderful example of a thermal garment we’re more than happy to wear loud and proud, UYN’s evolutyon pants rely heavily on natex, a hi-tech lightweight fabric that is similar to nylon but significantly tougher, and offers much quicker drying times (after all, nothing feels worse than slipping on damp, musty leggings that haven’t had time to dry properly).

An abundance of areas of breathability maximises comfort by aiding airflow. Meanwhile, thicker material around joints – areas especially prone to injury in cold weather – provides added protection, and Drylight technology (often referred to as absorptive knitting) provides fantastic sweat-wicking.

Thermal garments this light are a rarity, and we’re amazed at how well this close-fitting vest helps regulate temperature, keeping us warm without risking overheating. This is largely thanks to simple design features – such as larger sleeve holes – which are often overlooked, although there’s plenty of tech, too. The star of the show is merino wool, which has natural odour control and temperature-regulating qualities, while the moisture-wicking two-layer construction will keep you dry and comfortable all day.

Weather, do your worst, because these trousers are designed to keep the wearer warm, no matter what the elements are doing. That said, the trousers are also incredibly comfortable, thanks to the 100 per cent merino wool construction. Four-way stretch and patches of cordura fabric (incredibly tough synthetic fibre-based fabric) on the knees and seat (bum area, to you and me) crank up the comfort, while providing extra protection in the areas that need it most. As an added bonus, the wool is ZQ-certified, meaning it’s sourced in ways that meet the highest animal-welfare and environmental standards.

We’re suckers for flattering leggings, and the contoured profile of these ones worked wonders. These are a rarity in the sense they’re super soft but highly technical, with precision-engineered areas of breathability that enable air to circulate – even during long workouts. This is down to the combination of hardworking but sustainable materials, including kapok – a natural vegetable-derived fibre with similar qualities to wool – and Biolight, another plant-based fibre, known for its supreme softness. We also appreciated the generous length, because nobody wants cold ankles, after all.

Acai has crammed a supersized amount of tech into these thermal leggings, which can either be worn under items such as ski pants, or worn alone on cold days. They’re also designed with practicality in mind – we love the addition of a pocket, and the material is 100 per cent opaque (because, let’s face it, nothing’s worse than finding out your treasured leggings are semi-transparent, no matter how beautiful your booty).

Seam-free construction eliminates the risk of chafing – especially useful on garments made with thicker material, such as these – and we appreciated the addition of reflective tape on the leg, which will come in especially useful for winter walks on dark nights.

Yes, apparently, thermal knickers are now a thing. Although we were sceptical, we’re now total converts. Our initial concern related to breathability, because this isn’t an area where we’re overly keen to lock in heat. But the two-layer construction and brilliant temperature regulation (courtesy of a heavy reliance on polyamide) mean these are a joy to wear. However, although there’s plenty of freedom of movement, they are on the tight side – although one advantage of this is the contouring effect. In short, our bum has never looked better. What more could you want?