Firmness
Type
Hybrid
Depth (cm)
37
Number of Layers
4
Trial Period (nights)
Warranty (years)
5
Price Range
£399 to £599
Best Sleeping Position(s)
Certifications
Assessed from Coolflex's published specification for this mattress, captured September 2026, and from regular price comparison across our UK retail partners.
Cooling is the main draw here. The Cool Gel Memory Foam is infused with gel microbeads to regulate temperature, which means less of that clammy, sinking-in warmth traditional memory foam can create. The pillow top contains up to 1200 mini pocket springs, so the surface feels plush but still springs back rather than leaving body impressions. Underneath, up to 800 individually pocketed springs move independently, which means support goes where your body needs it and your spine stays aligned. The medium firmness suits most sleeping positions, and the from-price of £399 is honest value for a 37cm hybrid. A 5-year guarantee and free next day delivery round it off.
Key Features & what's inside
- Pillow Top. A plush pillow top with up to 1200 mini pocket springs, working like a stitched-in mattress topper. You get that soft, cushioned first touch without needing to buy a separate topper.
- Cool Gel Memory Foam. Memory foam infused with gel microbeads to regulate temperature and improve breathability, designed to draw heat away from the body. In practice, that means the contouring feel of memory foam with less heat build-up overnight.
- Comfort Foam. Layers of Comfort Foam that cradle pressure points and relieve pressure across the whole body. Side sleepers should notice this most around the hips and shoulders.
- Pocket Springs. Up to 800 individually pocketed springs that move independently to target support where you need it and keep your spine aligned. Independent movement also means less disturbance when a partner shifts position.
Layer details from mattressnextday.co.uk product page, September 2026.
Who's it NOT for?
If you prefer a firm, supportive surface, the plush pillow top will likely feel too soft. Heavier sleepers who need pronounced pushback may sink further than they'd like into the comfort layers. And at 37cm deep, it's a tall mattress: standard fitted sheets may struggle, so check yours first.
Coolflex Hybrid CHILL Mattress
Across owner reviews on mattressnextday.co.uk, where it holds a 4.9 rating from 72 reviews, customers praise its cooling properties and suitability for hot sleepers. The medium firmness is also noted as working well for all sleeping positions.
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Is the Coolflex Hybrid CHILL mattress good for hot sleepers?
Yes, cooling is its main selling point. The gel-infused memory foam is designed to draw heat away from the body, and owner reviews specifically praise its cooling properties. If overheating is your biggest complaint at night, this is one of the more sensible picks at this price.
How firm is the Coolflex Hybrid CHILL?
It's a medium. Combined with the plush pillow top, that gives a cushioned, forgiving feel that suits all sleeping positions according to owner feedback, although fans of a properly firm mattress should look elsewhere.
How many springs does the Coolflex Hybrid CHILL have?
2000 in total: up to 1200 mini pocket springs in the pillow top and up to 800 full-size pocket springs in the support base. Because they're individually pocketed, each spring moves independently, which helps with pressure relief and reduces partner disturbance.
What guarantee does the Coolflex Hybrid CHILL come with?
It comes with a 5-year guarantee, along with free next day delivery. Some brands offer longer cover, but five years is reasonable at this price point.
What sizes is the Coolflex Hybrid CHILL available in?
Five UK sizes: Single, Small Double, Double, King and Super King, with prices ranging from £399 to £599. Bear in mind it's 37cm deep, so you may need deep or extra-deep fitted sheets.
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