Dormeo Octasmart Essentials Cooling Mattress Topper im Test

The Dormeo Octasmart Essentials Cooling Mattress Topper is a 5cm topper that adds a Cool Touch cover to the Octasmart Essentials design, with an Octacell comfort layer in memory foam or firmer Aerocell foam on a foam base. It costs £249 for a UK double at the time of writing (September 2026). Only 12 buyers have reviewed it on Dormeo’s site so far, averaging 4.3 out of 5.

What the cooling claims mean

The Essentials Cooling topper page on dormeo.co.uk makes three cooling claims, all the manufacturer’s own.

The 40% figure is measured against a polyester cover, not against Dormeo’s other toppers, and Dormeo does not publish the test behind it. What is well established is why cooling matters. A 2012 review in the Journal of Physiological Anthropology (Okamoto-Mizuno and Mizuno) found that heat exposure increases wakefulness and reduces slow-wave and REM sleep, and that normal sleep goes with a bed climate of about 32 to 34°C. The room matters too: Bed Advice UK, the consumer site of the National Bed Federation, puts the ideal bedroom temperature at 16 to 18°C on hot nights.

Plush or Firmer

Both versions cost the same. Plush Comfort uses memory foam for a softer, cushioning surface; Firmer Support uses Aerocell foam and suits sofa beds, guest beds or sleeping on the floor. Dormeo rates the topper medium overall and suitable for front, back and side sleepers, and we score it 5 out of 10. At 5cm it meets Bed Advice UK’s minimum depth for a noticeable topper, but it will not hide a sagging mattress.

Prices by size

Trial and warranty

The topper has Dormeo’s 200-night trial. The Octasmart topper warranty covers the core for eight years and the removable cover for one, but only the first two years are full cover; from year three you pay a rising share of a replacement, 45% in the fourth year. As an Octasmart Essentials product it is excluded from free collection, so a return through Dormeo’s courier costs £45. It also costs the same as the 7cm Octasmart Plus topper in a double, which is worth knowing if you want cushioning as well as cooling.