Ergoflex 5G
8.2/10The Ergoflex 5G is a 23 cm memory foam mattress with 9 cm of…
Firmness: Medium firm · 30-night sleep trialThe Soak&Sleep Cooling Memory Foam Mattress is a 22cm medium-firm all-foam mattress with a gel-infused top layer and a 10-year guarantee.
The Soak&Sleep Cooling Memory Foam Mattress is a 22cm, medium-firm, no-turn foam mattress built from three layers, with a gel-infused quilted top meant to take the edge off the warmth memory foam is known for. It comes only in double, king and super king and arrives vacuum-packed and rolled. In a double it costs £30 more than Soak&Sleep’s own Zoned Hybrid Deep Memory Foam Mattress, a 24cm pocket-sprung hybrid, which is worth weighing if you are not set on all-foam.
Soak&Sleep lists the fill on its product page as gel-infused quilting over 5cm of memory foam and 15cm of base foam, under a quilted jersey polyester cover that zips off. The seller rates the feel medium-firm and suggests it for side sleepers.
| Layer (top to bottom) | Depth | Job in the mattress |
|---|---|---|
| Quilted jersey polyester cover | Included in total | Removable, zipped surface |
| Gel-infused quilting | Not stated | Cool-to-the-touch comfort layer |
| Memory foam | 5cm | Softens with body heat and moulds to shape |
| Base foam | 15cm | Depth and medium-firm support |
| Total | 22cm | No-turn, rotate head to foot |
For most adults, medium-firm is a safer default than firm. In a randomised trial of 313 adults with chronic low-back pain published in The Lancet in 2003 (Kovacs et al.), people given a medium-firm mattress were more likely to report less pain while lying in bed after 90 days than those given a firm one (odds ratio 2.36). That trial did not use this mattress, so read it as an argument for the firmness level rather than for the model.
The cooling claim needs context. Soak&Sleep’s own FAQ on the page concedes that memory foam mattresses “are known for being very warm” and points people who regularly overheat towards pocket springs with natural fibres. Gel makes the surface feel cool when you first lie down; it does not change how much heat the 20cm of foam underneath stores. The Sleep Charity puts the ideal bedroom at around 16 to 18°C and says temperatures over 24°C are likely to cause restlessness, so the room and your bedding will decide as much as the mattress.
The product page names CertiPUR and OEKO-TEX certification, without certificate numbers. Under EUROPUR’s CertiPUR scheme, label holders’ foams are tested every year by independent laboratories for restricted substances, and OEKO-TEX Standard 100 tests textiles against a list of more than 1,000 harmful substances. The mattress is designed in Denmark and made in China.
| UK size | Dimensions | Price |
|---|---|---|
| Double | 135 x 190cm | £315 |
| King | 150 x 200cm | £355 |
| Super king | 180 x 200cm | £425 |
Prices were checked on soakandsleep.com in September 2026. There is no single or small double.
Every new Soak&Sleep mattress comes with a 100-night trial, but the returns page asks you to sleep on it for at least 30 nights first and to use a mattress protector throughout, or the return can be refused. The product page gives a 10-year guarantee, twice the five years on the brand’s British-made Wool 2000. Soak&Sleep’s general returns and guarantee page, however, still says “up to 5 years on mattresses”, so keep the order confirmation or a screenshot of the product page as proof of the ten years. Mattress delivery is free to mainland UK postcodes; the delivery page also lists a £45 charge for non-faulty mattress returns, which does not sit neatly with the trial’s promise of free returns, so confirm the cost before you order.
| Brand | Soak&Sleep |
|---|---|
| Material | Gel-infused quilted comfort layer, 5cm memory foam, 15cm base foam. Quilted jersey polyester zip cover. No-turn, delivered rolled. 22cm deep. |
| Made in | China |
| Firmness | Medium firm (6/10) |
| Height | 22 cm |
| Sleep trial | 100 nights |
| Warranty | 10 years |
| Delivery | Free, rolled, UK mainland only |
| Available sizes | 135x190, 150x200, 180x200 |
| Overall score | 7.4/10 |
| Certifications | CertiPUR, OEKO-TEX |
“Buy the Cooling Memory Foam Mattress if you want medium-firm memory foam for a double or larger bed and value a 10-year guarantee over a big-name label. Skip it if you already run hot at night or need a single, because a gel top cannot fully offset the heat that 20cm of foam holds.”Go to shop →
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