The Therm-a-Rest EvoLite mattress

Therm-a-Rest originally made its name from its self-inflating foam sleep mattresses, then brought out a range of lighter blow-up mattresses that gained new fans but involved a session of huff-and-puff before you could stretch out at camp.

Now, the Seattle-based brand has combined the two technologies in its new EvoLite mattress.

A company spokesperson said: “Air mattress fans rave about ultralight compactness, while self-inflating mattress fans hold fast to stable comfort and convenience. Well, what if you could have both?

“At 480g (1lb 1oz), the EvoLite mattress hinges its blended technology on Atmos Foam, the lightest and most compressible foam on the market. Exclusive to Therm-a-Rest, the foam is poured in a closed, atmospherically controlled chamber that allows all gasses to be captured and ‘scrubbed’ before venting, ensuring precision control over uniformity and loft.

“Therm-a-Rest alternates foam and air channels to drastically reduce the weight of traditional foam mattresses while amplifying loft. At 5cm (2 in) of loft, no other lightweight, self-inflating mattress provides this amount of loft and comfort.

“Excellent self-inflation allows just a few breaths to top off the thick mattress for optimal firmness.”

The EvoLite has an insulation R-value of 2.1, which pitches it at the three-season level while its low weight means it will be attractive to mountain wild campers and backpackers who want to keep their pack weights down.

The Therm-a-Rest EvoLite is in the shops now, priced at £100. More details are on the Therm-a-Rest website.