Can this 'glacier' gel mattress truly tackle night sweats? Our expert put it to the test

Dreams TheraPur ActiGel Glacier 4800: £1,999 at Dreams

Dreams is the most reliable place to buy this mattress. They offer options like zip-and-link, Sleepmotion bases, and various firmness levels.

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Menopausal sleep is no joke. Hot flushes, night sweats, and the dreaded 3 am wake-up make restful nights feel like a luxury. So when we tested the Dreams TheraPur ActiGel® Glacier 4800, the question was clear: could a mattress called Glacier really help keep things cool in the heat of hormonal havoc?

Melanie, our tester in her mid-fifties, put the mattress through its paces alongside her husband - and the occasional pet co-sleeper. Spoiler: it impressed. "I actually woke up refreshed - something I haven’t said in years," she told us.

I pressed her for every detail to find out whether this really is one of the best cooling mattresses on the market. With its cooling foam, cooling gel, and 4107 coils, it just might be the one to spring into the top spot.

Dreams TheraPur ActiGel® Glacier 4800 review

Before diving into the details, I always like to give a quick overview of what a mattress is really like and who it's best for. The TheraPur ActiGel® Glacier 4800 is a firm hybrid mattress designed for cooling comfort and targeted support, making it ideal for hot sleepers or those dealing with night sweats.

With 4,107 springs (a mix of pocket and micro) and a 4cm layer of breathable ActiGel® foam, it offers pressure relief, airflow, and excellent motion isolation. A quilted pillow top and ActiCool® knitted cover add softness while helping regulate body temperature. It's a great choice for hot sleepers (due to the cooling gel), couples (thanks to low motion transfer), and anyone needing firm support through the shoulders, hips, and knees.

How we tested the Dreams TheraPur ActiGel® Glacier 4800

Before we get into the details of this Dreams TheraPur ActiGel® Glacier 4800 review, here’s a quick look at how we tested the mattress and who’s behind the review.

Melanie Blanksby

Melanie is a seasoned health writer with over two decades of experience as an independent freelancer. As someone currently navigating the challenges of menopause, including disrupted sleep, night sweats, and temperature fluctuations, she’s the ideal candidate to put cooling mattresses to the test. Melanie also shares a bed with her husband (and occasionally a large dog), so anything that claims to reduce nighttime disturbance is high on her radar.

Dreams TheraPur ActiGel® Glacier 4800 specifications

What's inside the Dreams TherPur ActiGel Glacier 4800?

I think it’s important to understand what you’re sleeping on - and why certain materials are used in your mattress. With the TheraPur ActiGel® Glacier 4800, Dreams has combined clever engineering with cooling technology to create a mattress that’s both supportive and comfortable throughout the night.

Inside are more than 4,000 springs, made up of both traditional pocket springs and smaller micro springs. These work together to respond to your movements and distribute weight evenly, helping to relieve pressure on areas like your shoulders and hips. Because the springs move independently, they also prevent that annoying 'rolling together' feeling if you share your bed with someone else. Around the edge, there’s added foam support so you can make full use of the mattress, even if you like to sleep right on the edge.

On top of the spring base is a layer of ActiGel® foam - a breathable, temperature-regulating material that helps keep you cool, especially if you’re experiencing hormonal changes or prone to overheating. This layer sits just beneath a quilted pillow top, so the cooling effect is felt close to your body. The top cover, made from ActiCool® fabric, is soft and specifically engineered to wick away heat, giving the mattress an instantly refreshing feel when you lie down.

Altogether, the materials inside this mattress create a sleep surface that's firm, cool, and supportive, helping you stay comfortable whether you're lying on your back, side, or sharing the bed. Dreamy, right?

Unboxing and setting up the Dreams TheraPur ActiGel® Glacier 4800

Getting a mattress delivered can be trickier than you might expect, so it’s always something I keep in mind when asking our testers to review a mattress. For the Dreams TheraPur, delivery went off without a hitch.

Melanie described the team as “really polite and helpful.” The king-size mattress was delivered flat - not rolled - and wrapped securely in protective polythene. It took two people to manoeuvre into place, especially onto an older wooden slatted cast iron frame, but once on, it fit snugly and reduced any frame creak or wobble. This is exactly what I would expect from a sprung mattress: you can't really roll up or compact springs too much.

Dreams has a wonderful reputation for helpful service, and they will help you as much as is reasonable.

Once the mattress was in place, Melanie noticed a mild new-mattress smell that faded within a few hours. “I’m really sensitive to smells, and I had no trouble sleeping on it that same night,” she told us. Again, that new mattress smell is always something that I would expect to note, especially on hybrid or foam mattresses. If you are hyper-aware of it, something as simple as opening a window or using an air purifier will help to settle things down.

What is the Dreams TheraPur ActiGel® Glacier 4800 like to sleep on?

Melanie tested this mattress for five months before sharing her verdict - a solid amount of time to uncover all the little quirks and details you’d want to know before investing.

The feature that most stood out to her was the cooling element. The top cover feels cool to the touch, which is an instant win for hot sleepers. “I spent a full five minutes just patting it,” Melanie confessed. “It’s synthetic, but still has a cool, almost silky feel that genuinely exceeded my expectations.”

Most mattresses range from about 23-30cm deep, so at 30cm, so this one sits right at the deep end of the spectrum. If you have shallow or older sheets, you’ll likely need to invest in deeper fitted sheets and a generously sized mattress protector, but it’s worth it.

Melanie used high-thread-count Egyptian cotton sheets, and while luxurious, they did slightly reduce the cooling sensation when paired with a thick protector, but if you can enhance the cooling properties with a cooling mattress protector and cooling sheets, you shouldn't lose much of the Therapur's offering.

The mattress is firm but forgiving, thanks to 2,694 pocket springs - plus even more micro springs - and a responsive layer of ActiGel® foam.

Melanie is predominantly a side sleeper, but found it ideal for both back and side sleeping. As someone who shares her bed and so is sometimes pushed to the edge, she particularly appreciated the reinforced edges, which discourage slumping. For me, this is always a really good indicator of the quality of a mattress. You want it to have the same tension right up to the edge so that you can enjoy the full expanse of the bed. If it's weak on the edges, you're limited in how and where you can sleep.

Very early on into testing (about a month in), Melanie messaged me with a quick update. “My husband stopped waking up with shoulder pain almost overnight,” she said. “He also fell asleep instantly and snored like a freight train, which was less charming.” Melanie is taking credit for bringing the mattress into their home because her husband has struggled with shoulder pain for a while. Given the blend of supportive springs and pressure-relieving foam, I'm not surprised that it worked well for injuries. It's certainly one of the greatest appeals of a mattress like the Dreams.

The mattress also passed the couple’s version of the bounce test: even a 34kg Goldendoodle jumping up didn’t cause the usual trampoline effect. Motion isolation is solid, and the whole structure stays put, even on an older frame.

Melanie characterised the TheraPur mattress as having a stable, motion-isolating core. Melanie and her husband noticed they didn’t need as many pillows, thanks to better back and shoulder support. And despite an occasional midnight shuffle or dog arrival, the structure remained firm.

The only slight disturbance, Melanie notes, is when “my husband hovered too long on the edge getting up, I felt that. But otherwise, the bed felt grounded and still.”

I was really interested to see how this performed as a cooling mattress, given the big, bold, cold claims made in just the name Dreams TheraPur ActiGel Glacier 4800. Melanie told me that she noticed the cooling effect straight away, but only when her mattress protector wasn't on. “On warmer nights, the ActiCool® layer really works if you’re just using a fitted sheet. With a mattress protector, it was harder to feel.”

There is a very simple fix for that: make sure your mattress protector is cooling too. I've tested plenty that work really well, so it is possible to enhance the cooling capacity with extra layers. Melanie did say that even with her protector, she woke up far less frequently with night sweats, and often didn’t need to throw off the covers in a fit of heat-induced rage. “If you're menopausal and sleep hot, this mattress makes a real difference.”

How does the Dreams TheraPur ActiGel® Glacier 4800 compare?

Cooling mattresses tailored for menopausal sleep can easily climb beyond £3,000. That’s another reason why the Glacier 4800 stands out. At £1,759 for a king size (RRP £2,199), it feels more high street than haute couture - but don’t let that fool you. It still delivers premium features that punch well above its price point.

Made in the UK, the Glacier 4800 offers smart, targeted cooling technology and genuinely supportive comfort. As reviewer Melanie puts it: “I’ve spent years styling my bedroom, but this proved that substance matters more than looks when it comes to sleep.”

If sustainability is your top concern, though, you might find the Glacier a little lacking. Beyond UK-based production and mattress recycling, it doesn’t boast standout eco-credentials.

That’s where I'd draw your attention to Button & Sprung's Southdown Mattress for a more eco-friendly alternative. It’s pricier, but also undeniably greener. Made entirely from natural materials, it’s fully recyclable at the end of its 10-year lifespan. You won’t get the same sink-in foam feel, but that’s part of its sustainability appeal, and it comes with the bonus of less of that telltale ‘new mattress’ smell. I think it's a competitive option.

Both mattresses are cool, supportive, and couple-friendly, but while the Southdown leads with sustainability, the Glacier 4800 is all about performance at a more accessible price. Which one is best for you depends on your priorities.

Should you buy the Dreams TheraPur ActiGel® Glacier 4800?

Given that Melanie has been the one sleeping on this for five months (and she still is), I asked her for the final verdict for this review. She said, "If you’re in perimenopause or menopause, sleep hot, or wake up with aches and pains, this mattress is worth considering. It's not the lightest or the most eco-luxe, but it delivers exactly what it promises: cooler nights, better support, and the real chance of a full night's sleep."