SleepSoul Cooler Ortho 4000 Series Pocket Gel Small Double Mattress
The SleepSoul Cooler Ortho 4000 Series is a firm hybrid mattress that pairs pocket springs with cool gel memory foam, which means you get orthopaedic-style support with less of the heat build-up foam is known for.
- Cool-touch cover for hot sleepers
- Firm, targeted spring support
- Hypoallergenic & vegan friendly
£449
Get the lowest price we've found
Save with the previous model
Some retailers still sell the earlier version of this mattress for less than the current model's best price.
SleepSoul Cooler Ortho 4000 Series Pocket Gel Mattress
More available sizes
Mattress details
Mattress
SleepSoul Cooler Ortho 4000 Series Pocket Gel Mattress
Size
Firmness
Firm
Construction
Foam
Pocket Spring
Hybrid
Memory Foam
Orthopaedic
Depth (cm)
26
Layers
3
Layer Details
Cooler™ Fabric Cover
A cool-feel knitted fabric cover that gives an instant cooling effect the moment you lie down. It also enhances breathability, helping air move through the mattress.
Cool Gel Memory Foam
Thick layers of memory foam infused with gel microbeads, which actively draw heat away from your body. That means the contouring comfort of memory foam without the warm, sticky feel it can sometimes have.
Pocket Springs
Firm pocket springs, each sitting in its own fabric pocket so they compress independently. This gives targeted support and pressure relief where your body needs it, rather than a uniform push-back.
Layer details from mattressnextday.co.uk product page, September 2026.
Key benefits
- Room to spread out alone: At 30cm wider than the UK single, it lets a solo adult lie starfish or roll over without an arm dropping off the side.
- Leaves floor space in tight rooms: Because it is 15cm narrower than the UK double, you may keep enough clearance for a wardrobe door to open or a bedside table to sit alongside.
- A sensible step up for teenagers: If your teenager has outgrown a single but their bedroom can't spare more floor, they gain width while the 190cm length stays exactly the same.
- Cooler feel in small, warm rooms: Compact bedrooms and loft conversions can hold heat, and the gel memory foam beneath the Cooler cover is designed to draw warmth away through the night.
- Fine for visiting couples: For a guest room used by the odd couple, the pocket springs compress independently, which means one person turning over should disturb the other a little less.
This size suits you if...
You sleep alone and want more stretching room than a single gives you, your bedroom or loft conversion can't take the width of a UK double, or it's a guest bed that couples use only now and then.
Consider another size if...
You share the bed every night, because two adults will find it tight over time. We'd recommend the UK double instead, which gives 67.5cm each; allow at least 2.6m x 2.8m.
Similar Mattresses in This Price Range
Did you know? On Mattress Unboxed we have over 1,000 different mattresses to suit all types of sleepers. View all mattresses.
FAQ's
Will a SleepSoul Cooler Ortho 4000 small double fit in a box room?
At 120 x 190cm it often will, though we suggest a room of at least 2.4m x 2.8m. Before ordering, measure how far your door swings into the room and check it still clears the bed once a frame is added, as frames usually sit a little larger than the mattress.
Is the SleepSoul Cooler Ortho 4000 small double big enough for a teenager?
For width, yes: the UK small double is 30cm wider than the UK single, so there's real room to turn. Length is the same as a single, though. If your teenager is very tall, the UK king is 10cm longer, but we suggest at least 2.7m x 2.9m for that size.
SleepSoul Cooler Ortho 4000 small double or double for a guest room?
If guests are mostly single visitors with the occasional couple, the UK small double suits and keeps more floor clear. If couples stay often, the UK double is 15cm wider and gives 67.5cm each. We suggest at least 2.6m x 2.8m for the UK double.
Does the small double SleepSoul Cooler Ortho 4000 suit a loft conversion?
It can suit a loft conversion well. With a sloping ceiling, the narrower footprint of the UK small double leaves more space at the side of the bed where you can stand upright. The gel foam and cool-feel cover may also help in a loft room that runs warm in summer.
How much bigger is the SleepSoul Cooler Ortho 4000 king than the small double?
The UK small double is 30cm narrower and 10cm shorter than the UK king. The UK king gives 75cm each for two sharing, so it's the better fit for couples every night, but it needs a room of at least 2.7m x 2.9m against 2.4m x 2.8m for the UK small double.