Last updated: October 2026
Memory foam is the material people either love or send back. It relieves pressure better than almost anything else, and it is also the reason for most "my mattress is too hot" and "I feel stuck in it" complaints. This guide explains what it is, what it does well, where it goes wrong, who should buy it, and why most of the UK market has moved to putting it on top of springs instead.
Quick answer: Memory foam mattresses are good for side sleepers, people with hip or shoulder pressure, and couples who want no partner disturbance. They are a poor choice for hot sleepers, heavier sleepers and anyone who changes position a lot, because dense foam traps heat, sinks under weight and is slow to move on. Cheap low-density foam also softens within a year or two. A hybrid, which puts a memory foam comfort layer over pocket springs, keeps the pressure relief and fixes the heat and support problems, which is why it is now the default recommendation for most people.
What is a memory foam mattress?
A memory foam mattress is made of viscoelastic polyurethane foam: a foam that softens in response to body heat and pressure, moulds to your shape, and returns to flat slowly when you move. An all-foam memory foam mattress has one or more layers of it over a firmer polyurethane base foam. There are no springs.
The material was developed for NASA seat cushioning in the 1960s and reached mattresses in the 1990s. Its appeal is simple: because it yields exactly where you press into it, the heaviest parts of your body (shoulders, hips) sink in and the lighter parts stay supported, which spreads your weight across the surface instead of concentrating it at a few points.
Three variations matter when you are shopping:
- Traditional (closed-cell) memory foam: the densest, slowest, most body-hugging type. Best pressure relief, worst for heat.
- Open-cell memory foam: the same material with a more open structure that lets air and moisture move through it. Noticeably cooler and quicker to recover. Our guide to open-cell foam explains how.
- Gel-infused memory foam: foam with gel beads or swirls added to pull heat away from the surface. Helps in the first hour, less so over a full night.
The pros: what memory foam does better than anything else
- Pressure relief. No other material cushions the shoulder and hip as well. For side sleepers who wake with a dead arm or a sore hip on a spring mattress, this is the fix.
- Motion isolation. Foam absorbs movement instead of transmitting it. A partner turning over, getting up early or coming to bed late barely registers on the other side.
- Silence. No springs, no creak.
- Contouring support for the lower back. Because the foam fills the gap at the waist, back sleepers often feel more evenly supported than on a flat, firm surface.
- Hypoallergenic surface. Dense foam gives dust mites less space to live in than traditional fillings.
The cons: why people stop buying memory foam
- It sleeps hot. Dense foam holds body heat and blocks airflow. This is the number one complaint and it is worse the more closely the foam hugs you. Open-cell and gel foams reduce it; they do not remove it.
- You sink and get stuck. Memory foam is slow to respond. Rolling over means climbing out of the dent you have made. Combination sleepers and anyone with limited mobility find this tiring.
- Heavier sleepers sink too far. Over about 14 to 16 stone, the comfort layers bottom out and the hips drop below the shoulders, which puts the spine into a curve. Thicker foam helps, but an all-foam mattress has no firm core to stop it.
- Cheap foam softens early. Durability tracks foam density. High-density foam (roughly 50 kg per cubic metre and above) holds its shape for years; low-density foam (under about 40 kg per cubic metre) can show permanent body impressions within one to two years. Most budget memory foam mattresses use the low-density kind.
- Off-gassing. New foam has a chemical smell for a few days. It is harmless and fades, but it puts some people off. Our guide to how long a mattress takes to expand covers it.
- Weak edges. All-foam mattresses compress at the sides, so sitting on the edge or sleeping near it feels unstable, and a couple ends up using less of the bed.
- Heat sensitivity. The foam is firmer in a cold room and softer in a warm one, so the feel changes with the season. Electric blankets soften it further; check the care label before using one.
None of these is a reason to avoid memory foam as a material. They are reasons to be careful about buying a mattress made of nothing else.
Who should buy a memory foam mattress
- Side sleepers under about 14 stone who get pressure pain at the shoulder or hip.
- Couples where one person is a light sleeper and the other moves a lot.
- People who sleep cool and like a close, cradled feel.
- Anyone who dislikes bounce and wants the bed to feel still.
Who should avoid it
- Hot sleepers. If you already throw the duvet off at 3am, all-foam will make it worse.
- Heavier sleepers. You need a firm support core under the foam, which means springs.
- Front sleepers and combination sleepers. Front sleepers need a flat, firm surface; combination sleepers need something quick to move on. Foam is neither.
- Anyone with back pain who has been told they need firm support. Foam contours; it does not hold. A firmer hybrid is the safer choice, and persistent back pain is a GP conversation first.
- Anyone on a tight budget. Cheap memory foam is the worst value in the market because it is the type most likely to fail early.
Is memory foam good for your back?
It can be, with two conditions. First, the foam must be dense enough not to let your hips sink below your shoulders. Second, the mattress must not be so soft that your spine bows. A randomised trial in The Lancet found that people with chronic low back pain did better on a medium-firm mattress than a firm one, and medium-firm memory foam over a supportive base fits that. Very soft all-foam does not.
The honest summary: memory foam is good for the pressure side of back pain (hips, shoulders, side sleepers) and weaker on the support side (lower back, back and front sleepers, heavier people). Our guide to the best mattress for back pain goes through this by sleeping position.
Why most memory foam mattresses are now hybrids
The industry's answer to the heat and sink complaints was not to abandon memory foam but to stop asking it to do the whole job. A hybrid mattress puts a memory foam comfort layer over a pocket spring core. The foam does what it is good at (pressure relief, motion isolation) and the springs do what it is bad at (airflow, support, edge stability, easy movement).
In practice that means:
| Complaint | All-foam memory foam | Memory foam hybrid |
|---|---|---|
| Sleeps hot | Common, worse with dense foam | Air moves through the spring core; open-cell foam on top |
| Stuck-in feeling | Slow to move on | Springs push back, easier to turn |
| Heavier sleepers sink | Bottoms out | Spring core carries the load; rated to 20 stone per sleeper on REM-Fit hybrids |
| Edges collapse | Yes | Reinforced edge springs |
| Softens early | Depends entirely on foam density | Springs hold the shape; foam layer is thinner and less load-bearing |
| Pressure relief | Best | Very good with a comfort layer of 5 cm or more |
| Motion isolation | Best | Very good with pocket springs |
The trade is a little less of the deep cradle for a lot less heat and a lot more support. For most people that is the right trade. Our memory foam vs hybrid comparison goes through it in detail, and memory foam vs spring covers the other end of the scale.
Every mattress in the REM-Fit hybrid mattress range is built this way: open-cell memory foam over a pocket spring core, 25 cm deep, in tensions from medium to orthopaedic firm. If you want the closest thing to the memory foam feel without the heat, the 5000 Lux Elite is the most contouring of the four.
REM-Fit 5000 Lux Elite Hybrid Mattress
The memory foam feel without the heat: cooling open-cell memory foam over 5000 dual-layer pocket springs at a medium-firm 7.5 out of 10. Good Housekeeping Approved 2026.
Shop the 5000 Lux Elite✓ 100-night trial (200 with a protector)✓ 15-year guarantee✓ Free UK delivery✓ 0% finance
If you do buy all-foam: what to check
- Foam density. Ask for it in kg per cubic metre. If the seller cannot tell you, assume it is low.
- Comfort layer depth. At least 5 cm of memory foam over the base, or the pressure relief is cosmetic.
- Open-cell or gel. Not optional if you run warm.
- Total depth. Under 20 cm and a heavier sleeper will feel the base.
- A trial of at least 100 nights. Memory foam takes two to four weeks to settle and for your body to adjust. A showroom lie-down tells you nothing.
- A guarantee that covers sagging, with the depth of dip it pays out on stated in writing.
If you are shopping across types, our guide to how to choose a mattress takes you through firmness, type and size in order.
Caring for a memory foam mattress
- Rotate, do not flip. Memory foam mattresses are one-sided. Rotate head to foot every three months.
- Use a breathable protector. Foam absorbs sweat and is hard to clean. A protector washes at 60C; the mattress does not wash at all. A cooling one such as the Tencel Cool protector keeps the airflow benefit.
- Keep it on a solid base with the slats close together, no more than about 7 to 8 cm apart. Foam sags through wide gaps.
- Air it. Pull the duvet back for an hour in the morning so moisture leaves the foam.
- Add a topper if the surface softens but the base is still sound. Our memory foam topper guide explains when that works and when it does not.
Frequently asked questions
Are memory foam mattresses good?
For side sleepers, couples and people who want pressure relief and a still bed, yes. For hot sleepers, heavier sleepers and people who move a lot, an all-foam mattress is usually the wrong choice. A memory foam hybrid suits a much wider range of people because the springs fix the heat and support problems.
What are the disadvantages of a memory foam mattress?
Heat retention, a slow stuck-in feel, sinking under heavier sleepers, weak edges, a new-foam smell for a few days, and early softening if the foam is low density. All of them are worse in cheap all-foam mattresses and most are solved by putting the foam over pocket springs.
Why are people no longer buying memory foam mattresses?
They are, but as hybrids rather than all-foam. The two complaints that drove people away from all-foam, heat and sinking, are exactly what a pocket spring core fixes, so the market moved to memory foam over springs. All-foam now sells mainly at the budget end and for people who specifically want the deep cradle feel.
Is memory foam good for back pain?
Good for pressure-related pain at the hips and shoulders, less reliable for lower back support. If you need firm, level support, choose a medium-firm or firm hybrid with zoned springs rather than soft all-foam, and see a GP if the pain persists.
How long does a memory foam mattress last?
Seven to ten years for high-density foam on a good base; as little as two to three years for low-density foam. The first sign of failure is a permanent dip where you sleep that does not recover during the day. Our guide to how often to replace a mattress lists the other signs.
Do memory foam mattresses get too hot?
Dense, closed-cell memory foam does. Open-cell and gel-infused foams are cooler, and a hybrid with a spring core underneath is cooler again because air can move through the mattress. If overheating is your main problem, the mattress type matters more than any cooling cover.
Memory foam or pocket sprung: which is better?
Memory foam wins on pressure relief and motion isolation; pocket springs win on airflow, support and ease of movement. A hybrid combines them, which is why it is the usual recommendation. If you must choose one, side sleepers lean memory foam and back, front and heavier sleepers lean pocket sprung.
Can you flip a memory foam mattress?
No. Nearly all memory foam and hybrid mattresses are one-sided, with the comfort layer on top and the support layer underneath. Rotate it head to foot instead.
Sources: Kovacs FM et al., The Lancet, 2003 (medium-firm vs firm mattresses for chronic low back pain); Sleep Foundation, memory foam mattress guides; REM-Fit product specifications, October 2026.
