Kathmandu’s “XT” series is starting to gain a name in the competitive space of high-end adventure clothing and equipment. Kathmandu’s visible focus these days is skewered towards outdoors-stylised street-wear fashion (teenagers are now wearing Kathmandu tops to the shopping mall, and when that happens you know it must be cool). This begs the question as to whether the company can still cater for true adventurer-seekers, while also accommodating more urban fashion trends?

The XT Exmoor is marketed as a kind of do-it-all jacket. The jacket is constructed using the increasing trend within the outdoor clothing sector to label everything with futuristic sounding and trademarked materials, including Polartec™ Alpha™ Direct™ and Pertex™ Quantum Air fabric. The main boast of all these fancy names is that the material is designed to regulate your body temperature, meaning you won’t have to add or remove layers.

At first I was sceptical. The jacket is neither waterproof, nor is it made of down, or any other material I instantly recognised as having heat-insulating properties. What was the purpose of jacket then? Was it just a glorified windcheater? Exceptional breathability is hardly a unique claim with these types of garments so I was interested to see how much uphill grunt (or not) it would take to get the thing steaming.

The jacket feels light in the hands and doesn’t exactly pack down small when you try to fold or roll it up. It billows out with huge air pockets and unravels easily, not a great thing when you’re looking to save space in your pack.

I was happy to find it comes with a pocket (literally sewn into a pocket) for the jacket to pack into itself and zip up tight. There are general instructions on how to fold the jacket into a rectangle, which I couldn’t for the life of me work out. But stuffing it like a sleeping bag seemed to work. Once packed away within itself it is quite compact.

The most striking feature of the jacket is the vivid red inside lining. It’s soft, fluffy and feels quite wonderful against the skin. This is the famed Polartec™ insulation layer. The material is a kind of wonder-fabric. It’s constructed with air pockets that trap air and retain body heat. Lofted-knit fibres are connected to a solid mesh core.

The aim is to “increase thermal adaptability in changing conditions and different phases of physical activity.” To translate the jargon, this means the jacket should feel warm – but not too warm – whether you’re sitting still with a cold wind blowing or climbing a steep track wearing a heavy pack. Moisture from perspiration is wicked away from the body, while cold air is kept out. On the outside a water-repellent layer does the job of protecting you from light showers, however I would pair the jacket with a full water-proof jacket if being out in the rain for any prolonged period of time.

So does the jacket actually stack up to its brave thermo-regulating claim? Short answer: yes. I tested it out in a variety of environments, some freezing and mountainous, some benign and warm. The big test was in the Victorian Alps, on a climb up Mount Wills after a heavy July snow dump. The sun was out and although the temperature was in the single figures I suspected the stiff climb would have me overheating before long. I wore a cotton t-shirt under the XT Exmoor and after half an hour of solid grunt I felt warm, but not overheating at all. We stopped for a rest and I unzipped the jacket. I was surprised to find the t-shirt soaked in sweat, but the jacket seemed as dry as ever. Cotton t-shirts are never a good idea in these conditions so I took that off and wore the jacket as my only layer as I continued to climb. I also discovered the Polartec™ feels amazing against the bare skin. I couldn’t have been more impressed. My companions sweated it out in poly-prop tops but I maintained a comfortable temperature, whether on the move or at rest. It passed the breathability test, but what about warmth? That test would come during the long afternoon and night at Mount Wills Hut.

The temperature plummeted as the day wore on. My hands and face froze. My fingers were beyond numb and stung with pain. But the XT Exmoor kept my torso and arms warm, no matter how cold the rest of me was. We slept on the floor of the hut and overnight as the fire died, the temperature dropped well below zero. Everyone had an uncomfortable night, even in good sleeping bags. Again my hands and face stung with cold, but I never felt a need to add a layer to my body. In fact, throughout the whole trip I never once got out the poly-prop or merino tops I had brought along as insurance. The jacket was light enough to be able to wear all evening in the hut without feeling cumbersome or overwrought, due to how light and airy it is.

Another nice feature of the jacket is the hood. It seems to swivel with your head as you turn from side to side, never obscuring your vision, and it’s also snuggly lined with Polartec™.

Are there downsides? After a few weeks of constant wear I’m noticing the zipper starting to get stuck more often. It’s a struggle to find the sweet spot, something you don’t want when you’re putting on the jacket in the elements with cold hands. Also, stuffing it inside its pocket isn’t a fun task, and you sometimes need three hands to get the zip closed once it’s successfully stuffed.

For me, the real value of this jacket comes down to two factors: its performance in its intended environment, the outdoors, for which it scores very highly. And also its versatility. Even the most hardened and extreme adventurer is likely to spend more time at home and in urban environments than in nature, so you want a jacket that you can wear everywhere. The dark colour is not the best if you want to be seen in the outdoors, and that’s another downside, but what value can you place on fashion? That’s for you to decide. A jacket that sits in the cupboard 95% of the time isn’t really doing you much use.

I’ve worn this jacket to the city to run errands; I’ve worn it to the shops, while walking the dog, visiting friends. I reach for it just about every time I leave the house. I wear it around the house; in fact I’m wearing it right now, while I type these words at the computer. It doesn’t matter what you’re wearing underneath, it has a magic way of keeping you at just the right temperature. Perhaps you can have it both ways after all?