Steph Wetherell has had some of her best ever camping sleeps on this Therm-a-Rest Neoair XTherm NXT mat. Find out why she rates it.

The Therm-a-Rest Neoair XTherm NXT is one of top performing four season sleeping mats available, touted as having the best weight to warmth ratio on the market, and it really does live up to the hype.

Steph Wetherell’s Best in Test

At this price point there’s no doubt that it’s an investment item, but for cold sleepers or those venturing into winter, it’s an investment worth making.
Pros
  • very insulating
  • lightweight
  • packable
Cons
  • expensive
Quick specs
Price: $239.95 / £270 (available from Cascade Designs)
Weight: Regular (440g), Regular wide (550g), Large (570g), MAX regular wide (650g), MAX large (680g)
Type: Air
Materials: 30D ripstop Nylon top, 70D Nylon bottom
Dimensions: Regular (51cm x 183cm), Regular wide (64cm x 183cm), Long (64cm x 196cm)
Thickness: 7.62cm
Rating: R value 7.3
Sizes: Regular, regular wide, long, MAX large, MAX wide
cascadedesigns.com

It has an R value of 7.3 and is by far the warmest mat I’ve ever slept on. The insulation comes by way of two features: a ‘Triangular Core Matrix’ construction, made up of two stacked layers of triangular chambers that creates cells that help capture warmth, and the ‘ThermaCapture’ technology that radiates heat back at you. I was sceptical, but even as a cold sleeper, I genuinely felt warm even when temperatures dipped below zero.

Previous versions of this mat were famous for sounding like you were sleeping on a crisp packet. I’m pleased to report that this version has greatly improved on this (apparently an 83% reduction in sound), and I found that it was really quiet once I was lying down.

As a plus-size person, I trialed the Regular Wide mummy version. I found it a comfortable width and could lie comfortably on my back or easily turn from side to side without the risk or falling off. The Regular is 13cm narrower so it may be worth opting for the wider option if you like a bit more space. There is also a MAX large and MAX wide if you prefer a rectangular mat to a mummy shape.

It's sweet dreams for Steph on the Thermarest Neoair XTherm NXT. Credit: Steph Wetherell
It’s sweet dreams for Steph on the Thermarest Neoair XTherm NXT. Credit: Steph Wetherell

It was very easy to inflate, with a large pumpsack that is easy to attach. The Winglock valve makes it easy to make small adjustments lying down without accidentally letting out all the air. It’s also easy to roll up and comes with a bag it actually fits into!

I genuinely had some of my best ever camping sleeps on this mat. At this price point there’s no doubt that it’s an investment item, but for cold sleepers or those venturing into winter, it’s an investment worth making.

Testing conditions

Steph tested her camping mats across hills and valleys in South Wales during winter and spring. She is plus-size and 5’10 tall so prefers a wider mat and sleeps cold so tends to opt for higher R-value mats. This review was published in the December 2025 issue of The Great Outdoors.