Therm-a-Rest NeoAir XTherm NXT Sleeping Pad: lightweight but warm year-round

Meet the reviewer

Therm-a-Rest NeoAir XTherm NXT Sleeping Pad: first impressions

Inflatable sleeping pads have come on leaps and bounds since I started hiking 16 years or so ago. I’m a notorious cold sleeper and can be found using a hot water bottle for 11 out of 12 months of the year, even inside. I was therefore interested to learn that the Therm-a-Rest NeoAir XTherm was pitched at those sleeping in cold winter and alpine climates. Since the introduction of the R-value rating in sleeping mats to provide better information for consumers, it’s now much easier to understand which seasons a sleeping mat is effective in. I tested the Therm-a-Rest NeoAir XTherm NXT while bikepacking in Fairbourne in mid-Wales and was pleasantly surprised by the brilliant warmth to weight ratio.

• List price: $239.95 / £260
• Weight: 1lb / 440g (regular); 1lb 3oz / 540g (regular wide); 1lb 4oz / 570g (large)
• Dimensions: 20 x 72 x 3in / 51 x 183 x 7.6cm (regular); 25 x 72 x 3in / 64 x 183 x 7.6cm (regular wide); 25 x 77 x 3in / 64 x 196 x 7.6cm (large)
• Packed dimensions: 9 x 4.5in / 23 x 11cm (regular); 11 x 5in / 28 x 13cm (regular wide); 11 x 5in / 28 x 13cm (Iarge)
• Color: Neptune
• Compatibility: Trekking, alpinism, mountaineering, thru-hiking

To work out how R-values are calculated, in simple terms it means giving a grade to the effectiveness of insulation products based on what they’re made of. This is done by dividing the thickness of a material (in meters) by its thermal conductivity. The NeoAir XTherm NXT is the best in class, with an R-value of 7.3. A mat with a high R-value is a no-brainer for those who are looking for a high-performance mat for sleeping out in the mountains, or just want the reassurance that they’ll get a comfortable night’s sleep without the worry of being woken up due to the temperature shift.

Therm-a-Rest NeoAir XTherm NXT Sleeping Pad: in the field

Weighing in at just 440g, the regular XTherm NXT mat is one of the most innovative and technologically advanced mats Therm-a-Rest has ever made. Combining a tough 70D nylon on the base of the mat and 30D rip HT nylon on the top, the sleeping mat takes the best of each fabric to make a mat that’s durable and reliable for multiple days’ usage, yet is not so heavy and bulky that it’s too heavy to carry. Use of the 70D makes it resistant to damage from packing down every day, whilst the 30D ripstop nylon on top keeps it lightweight.

There’s no other sleeping mat that comes close to the XTherm NXT – for cold sleepers, having a mat that uses the best tech to deliver a great weight to warmth ratio is a gamechanger. Therm-a-Rest has used its Triangular Core Matrix construction – which is effectively two layers of triangle baffles edge-to-edge – to slow convective heat loss. The cells then create a stable internal space to provide support. Meanwhile, the ThermaCapture technology involves a lightweight reflective material (like you’d see in a foil blanket) that’s placed inside to help redistribute heat back to the body and minimize cold spots. Both aspects of construction reduce overall convective heat loss without adding weight or bulk to the sleeping mat.

For a back sleeper, having a thick sleeping mat is important to provide cushioning and comfort from the ground. A chunky thickness gives cloud-like comfort at an impressive 3-inch (7.6-cm) thick profile, whilst a horizontal baffled structure allows weight to distribute evenly without the awkward sleeping mat sag.

To get the sleeping mat ready, it’s rolled up with all the air removed to create a compact package. Often the most common problem with pack down is trying to get the sleeping bag to fit back in its original packaging. Thankfully the WingLock Valve allows for rapid inflation, so air doesn’t accidentally escape, and it’s also straightforward to ‘dump’ air on deflation. The valve lock is also easier to operate than a popper style closure, meaning it’s easy to use in cold or wet weather when gloves are staying on. A pump sack (the kind where you waft air in) attaches onto the valve lock, so once you get into the rhythm of how much air to put in, it’s easy to fill the mattress up.

Sleeping mats (especially inflatable ones) often rustle, as sleepers move in the night due to shifting sleeping positions, temperature changes or discomfort. If you’re sharing a tent with someone, the sound of sleeping bags against the mat can be a major annoyance to your fellow campers. On the XTherm NXT, comfort and warmth can be easily adjusted by small tweaks on the inflation valve. Meanwhile, the material is comfortable enough to sleep on without being so shiny you slip off.

The Therm-a-Rest NeoAir X Therm NXT comes with the sleeping mat, pump bag, and repair kit, stowing away into a stuff sack pack that’s not much bigger than a 1L Nalgene bottle. It's a big win for those who look at challenging themselves in fast and light terrain, yet don’t want to have a night of suffering as a result.

• How Advnture tests products