The Therm-a-Rest NeoAir XTherm is a four-season insulated sleeping pad ideal for mountaineers, ski tourers, and winter backpacking of any type. Therm-a-Rest claims that it provides more warmth per gram than any other sleeping pad in the world. This is a bold claim, but we have found no evidence to the contrary. It is available in Regular and Long lengths.

Warmth

With an R-Value of 5.7, coupled with impressively low weight, this is the warmest pad that is small and light enough for backpacking. The only pad with a higher R-value in our insulated sleeping pad test was the Luxury Map, which is a thick, large, and heavy car camping mattress. The NeoAir XTherm is far and away from the warmest lightweight pad that we tested.

The XTherm manages to be the warmest by a combination of two technologies: NeoAir’s triangular core matrix, which is 2 stacked layers of triangular baffles on the interior of the pad. This minimizes convective heat loss to the cold ground. Second, the XTherm features a reflective coating called Thermacapture that bounces radiant heat back towards the sleeper.

Comfort

With 2.5 inches of inflatable cushion, the NeoAir used to be the leader in air construction comfort. Now there are several other inflatable mattresses on the market that we think feel more stable and are overall more comfortable, such as the Sea to Summit air-sprung cell design that is found on both the Comfort Plus and the Women’s Etherlight. However, the Xtherm is plenty comfortable, even for sleeping on for a couple of weeks at a time, as we did in Alaska during our test.

Weight

The low weight and small packed size are what make the XTherm such an impressive product. On our scale, it weighed 15 ounces even. The only pad that weighed less was the Big Agnes AXL, and that pad does not provide adequate insulation for sleeping on snow. The XTherm does. We highly recommend this sleeping pad for any winter backcountry adventure where weight is a concern.

Packed Size

The XTherm also packs down quite small with a packed size of roughly 9×4 inches. Again, the only one that was smaller was the Big Agnes AXL, but that pad is only appropriate for summer use. For a four-season sleeping pad, the XTherm cannot be beat in its low weight and small size.

Durability

We experienced no durability issues with the XTherm during our testing period, and we slept on it a lot. With 30 denier nylon on the top and denser 70 denier nylon on the bottom, it is prepared for use on uneven surfaces. We anticipate that it will hold up to a fair bit of use if treated with care.

Ease of Use

The main downside to the NeoAir XTherm is the amount of time it takes to inflate. All testers agreed this was a pain. However, the trade-offs in low weight and impressive insulation are worth this reduction in ease of use. The NeoAir is also loud to sleep on, which some people cannot stand. Most of us get used to it after a while.