Arthur Sleep Cool Comfort Mattress
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Mattress
Arthur Sleep Cool Comfort Mattress
Size
Firmness
Medium
Construction
Pocket Spring
Depth (cm)
Layers
5
Layer Details
Gel foam
A cooling gel foam sits at the top to counteract the heat retention of memory foam and keep the surface breathable. If you tend to overheat, this is the layer that matters most.
Memory foam
Memory foam works with the gel layer above it to give body-cradling comfort. You get that gentle, sink-in contouring, with the gel there to take the edge off the warmth.
Comfort foam
A dense layer of eco-high resistance PU foam that gives a soft, cushiony feel. It adds support beneath the softer layers above, so the top doesn't feel too sinky.
Convoluted foam
High resilience convoluted foam spreads your body weight evenly for targeted pressure relief. It should help the mattress ease off heavier areas such as hips and shoulders.
Encased foam edge
A 10cm encased foam structure surrounds the pocket springs for extra support and stability. It should make the sides feel steadier when you sit on the edge or sleep close to it.
Layer details from arthursleep.co.uk and mattressman.co.uk product pages, October 2026.
- Real room to spread out alone: At 120cm across, the UK small double is 30cm wider than the UK single, which means a solo sleeper can change position without meeting the edge.
- Fits compact bedrooms: It is 15cm narrower than the UK double, so a box room, studio or loft conversion keeps walking space that a bigger bed would swallow.
- Cooling where you actually lie: The foams are designed to draw heat away rather than trap it, useful in small rooms where warm air has nowhere to go.
- Pocket springs for occasional sharing: Springs that move independently mean a guest room couple feel less of each other's movement, even on a narrower bed.
- Standard 4ft sizing: The small double is a standard UK size, so frames and fitted sheets are easy to find rather than a specialist order.
This size suits you if...
You sleep alone and have outgrown a single but your room cannot take a full double, or you're furnishing a guest room or holiday let where couples stay for the odd night rather than every night. It also fits a teenager's room where floor space still matters. Allow at least 2.4m x 2.8m so the door clears and you can walk round the bed.
Consider another size if...
You share the bed every night, because 120cm is snug for two over the long term. We'd recommend the UK double instead, which is 15cm wider and needs a room of at least 2.6m x 2.8m.
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What size room do I need for a small double mattress?
We suggest a room of at least 2.4m x 2.8m for the UK small double. That allows the door to open fully and leaves walking space on at least one side. In a box room or studio, measure before you order: the difference between 120cm and 135cm of bed width often decides whether the layout works.
Is the Arthur Sleep Cool Comfort small double big enough for a couple?
For occasional nights, yes. The pocket springs move independently, so a visiting couple in a guest room won't disturb each other much. For nightly sharing, 120cm is tight, and we'd recommend the UK double of this mattress instead, which adds 15cm of width and suits rooms of at least 2.6m x 2.8m.
How much bigger is the small double than a single?
The UK small double is 30cm wider than the UK single, and the two are the same length at 190cm. That extra width is the whole point of this size: a teenager or solo adult gets proper room to spread out without the jump to a double's footprint.
What bed frame does the Arthur Sleep Cool Comfort small double need?
A standard UK 4ft frame. The small double is a common UK size, so frames, fitted sheets and mattress protectors are widely stocked. Most people pair it with a standard double duvet, which drapes generously over the narrower base.
Is the small double a good choice for a loft conversion or rental?
Often, yes. Sloping ceilings and small second bedrooms tend to rule out a 135cm double, and the small double's 120cm width can preserve standing room beside the bed. One caveat: Arthur Sleep doesn't publish a firmness level for this mattress, so if a specific feel matters to you or your tenants, ask the brand first.