The Tensor Extreme sleeping mat is being hyped as ‘the warmest, most insulating pad on the market’, so I was intrigued to try one out in real winter conditions. It’s a thick air mat with a grid-based baffle structure and 4 layers of heat mirroring foil inside.

Unfurled in the shelter, the regular wide takes up a fair bit of room but is very, very comfortable. The grid baffles make for a stable, flat surface, and that, combined with the width really aids a comfortable night’s rest. I was in no danger of falling off the edges and the bluesign approved fabric feels durable and robust. It’s very quiet when moving or turning over, too.

David Lintern Recommends

Overall, it’s a durable and comfortable option very cold conditions, but it may be overkill for most of the year.
Pros
  • Comfort
  • Warmth
Cons
  • Weight
  • Cost
Quick specs
Price: £249.50 (same in dollars)
Weight: 755g (Regular wide)
Type: inflatable air mat
Materials: 20D GRS certified Nylon, Bluesign Approved, aluminised film insulation
Dimensions: 183x64cm
Thickness: 9cm
Rating: 8.5
Sizes: Regular, Regular mummy, long wide, regular wide
Women’s version: unisex
www.nemoequipment.com

Inflation is via supplied bag, which prevents condensation building up inside the mat and improves durability. It takes 4 bags at 30 breaths each. The bag is high quality, with a rubberised seal at the folding end and a nozzle that interfaces with the 2-way valve without popping off (at least when new) – a practical system that doesn’t take too much time or energy, especially given the size of the mat. It is easy to fold away and is surprisingly compact when packed. Given it weighs ¾ of a kilo, it doesn’t feel too heavy in the rucksack, either.

I tested the Tensor Extreme during the coldest nights of the 2023 winter season. High on the Cairngorm plateau, ground temps were around -14C, and I felt the cold a little through the mat. The second night out was a balmy -2C, and I felt no cold.

Overall, it’s a durable and comfortable option very cold conditions, but it may be overkill for most of the year. A repair kit is included, but if I were taking somewhere even colder, I’d still want a reserve mat to stack with, or in case of complete failure.