We have a complicated relationship with memory foam. We love the way it hugs and hate the way it holds a grudge, meaning the way a traditional foam mattress absorbs every degree of body heat you give it and hands it right back at 3 a.m. like a wet, warm blanket you didn’t ask for. So when SweetNight Mattress rolled out the CoolNest Ultra, a memory foam mattress whose entire personality is “we fixed the heat thing,” we wanted to see whether the pitch survives contact with an actual hot sleeper.
Bottom line up front: the SweetNight CoolNest Ultra is an all-foam mattress that treats cooling as a five-layer engineering problem instead of a marketing adjective, and for hot sleepers, side sleepers, and couples, it offers a strong combination of cooling, pressure relief, and support at a price point under $1,000.
We want to tell you the story of the whole SweetNight sleep system, because SweetNight didn’t stop at the mattress. There’s a CoolNest cooling comforter and a matching cooling pillow built on the same fabric technology, and once you’ve slept on a cool mattress, a hot comforter on top of it is a betrayal. More on that later. Mattress first.
Review: What the SweetNight CoolNest Mattress Actually Is
The CoolNest Ultra is SweetNight’s 2026 flagship all-foam mattress. Not a hybrid, not a latex mattress, not an organic mattress with wool and a price tag to match. It’s a memory foam mattress, full stop, built in seven layers, sold in three heights, and priced from $729.99 to $1,029.99 depending on size and thickness.
The quick specs, for skimmers:
- Mattress types available: all-foam only for the Ultra (SweetNight sells a separate CoolNest Hybrid if you want coils; more on that below)
- Heights: 12, 14, and 16 inches
- Mattress sizes: Queen and King (SweetNight says Twin and Full are coming later this year; at press time, the mattress is available in the two big sizes only)
- Firmness: the 12-inch is Medium; the 14-inch and 16-inch are Medium Plush
- Certifications: CertiPUR-US certified foams, OEKO-TEX Standard 100 cover, ACA-endorsed (American Chiropractic Association), ISPA member, fiberglass-free
- Trial and warranty: 100-night trial with free pickup and a full refund, 10-year warranty
That last bullet matters more than it looks. A 100-night trial period is how you actually test the SweetNight CoolNest instead of trusting a stranger on the internet (hi), and SweetNight itself recommends sleeping on the mattress for at least 30 nights before deciding. Foam needs time; so do your hips.
The Seven Foam Layers
Every mattress company gives its foam layers names that sound like skincare. SweetNight is no exception, but the layers do different jobs, so here’s what each one is actually doing under you.
1. Gradient Cooling Ice Silk Cover. The top fabric. This is the cool-to-the-touch layer, rated at a Q-Max of 0.25, which SweetNight says is about 47% higher than a standard cooling fabric. Translation: it feels cold when you lie down, and the sleep surface stays fresher than plain foam. The cover also has over 10,000 micro-pores per square centimeter, which is a wild thing to know about a sheet of fabric, but it’s why the surface wicks heat and moisture instead of trapping it.
2. PCMflux High Resilience Foam. The first foam layer, and the clever one. PCM stands for phase change material, a substance that absorbs heat when you’re too warm and releases it when you cool down, like a very patient ice pack that never leaks. SweetNight infuses this foam with what it calls twice the PCM and gel particles of its traditional model, and gives it a hollow large-pore structure for airflow. This is the “balances temperature all night” layer rather than the “chilly at first” layer.
3. AirMesh Breathable Memory Foam. Memory foam is usually closed-cell, which is why it hoards heat. AirMesh is SweetNight’s open, hollow-mesh memory foam, which the brand says delivers up to 6× the breathability of traditional closed-cell memory foam while keeping the contour and pressure relief you buy memory foam for in the first place.
4. Ventilated Gel Memory Foam. A gel-infused memory foam layer (30% gel particles) with 700-plus perforations. The infusion pulls body heat away; the vents let it escape. Together with the AirMesh layer, this comfort layer keeps a memory foam mattress from turning into a memory foam sauna.
5. 7-Zone Ergonomic Support Foam. Wavy-cut support foam gives the mattress shape memory for your body, not just your body heat. Seven zones (head, shoulders, back, waist, hips, legs, feet) with different firmness. This is where pressure relief and support stop being a trade-off and start being a layout. The wave shape also creates airflow channels at the base, so the support layer is quietly part of the cooling system too.
6. Enhanced Stability Support Foam. High-density base foam. This layer keeps the mattress from sagging and is why the warranty covers sagging at all.
7. Durable Anti-Slip Dotted Fabric Base. A textured bottom fabric so the mattress doesn’t scoot around on your bed frame when you roll over. Small thing. The kind of small thing you notice at two in the morning when your old mattress has migrated four inches toward the wall.
SweetNight’s Advanced CoolNest® Ultra System combines multiple cooling layers and breathable structures throughout the mattress, working together as a five-stage cooling process from cool and balance to absorb, reduce, and release, designed to deliver up to 11° cooler sleep. We can’t verify the number in my bedroom without a lab, but the logic is sound: each layer handles a different phase of heat, from first touch to 4 a.m., instead of one gimmick cover doing all the work and quitting an hour in.
How the SweetNight CoolNest Mattress Feels: The Cool Night Sleep Experience
Medium Plush is the honest description for the 14- and 16-inch, and it’s exactly what it sounds like: you sink in, the foam catches you, and it doesn’t feel like quicksand. The 12-inch runs Medium, offering a slightly firmer feel.
A few feel notes, sorted by what people actually ask:
- Contour and pressure relief. This is memory foam doing memory foam things, and pressure relief is its best. The hips and shoulders get cushioned, the foam conforms to your shape, and pressure points spread out instead of getting ground in. The 7-zone support foam keeps the contour from sinking too deeply, which is the difference between “hugged” and “trapped.”
- Surface temperature. Chilly at first touch thanks to the Ice Silk cover; balanced through the night thanks to the PCM and vented layers. Every cooling cover loses some of its initial chill once you’ve been in one spot a while, but the whole point of the five-stage design is that the layers under the cover keep working after the cover’s first impression fades.
- Motion transfer. All-foam mattresses are naturally good at motion isolation, and SweetNight lists it as a feature here. If you sleep with a partner who does interpretive dance in their sleep, this is a real benefit: multiple layers of memory foam reduce motion transfer so their position changes don’t become your interruptions.
- Edge support. Here’s the honest part. SweetNight does not claim strong edge support on the Ultra, and its own product page calls it average. That’s typical for an all-foam mattress. If you sit on the edge of the mattress to put your socks on every morning (this is where a soft mattress shows its limits), or you’re a couple who sleeps at the outer limits of a Queen, a hybrid with a reinforced coil perimeter will give you better edge support. If you sleep in the middle like a normal person, you’ll never think about it.
- Off-gassing. Standard for a mattress in a box. SweetNight recommends letting the mattress expand for 48 to 72 hours after unrolling. SweetNight recommends letting the mattress expand for 72 hours after unrolling. The foams are CertiPUR-US certified, and the new-mattress smell fades in a few days.
Who Sleeps Best on the SweetNight CoolNest Ultra (Better Sleep by Sleep Position)
A mattress is only the best mattress for the person it fits. Sleep position is the biggest variable, so let’s sort by that, with the best pick for each and the honest caveat where there is one. Your needs and preferences decide the height; the cooling system is the same across the whole Ultra lineup.
- Best mattress for side sleepers: the 14-inch or 16-inch Medium Plush. Side sleepers need their hips and shoulders to sink enough to keep the spine straight, and the extra comfort foam on the taller builds gives the best pressure relief in the lineup. Pressure-sensitive side sleepers who wake up with a numb arm on firmer beds are the sweet spot for this mattress.
- Best mattress for back sleepers: the 12-inch or 14-inch. Back sleepers want contour under the small of the back and support under the hips; the 7-zone foam is designed for exactly that, and it’s the best argument for the mattress if alignment matters more to you than plushness, and the ACA endorsement is about spinal alignment, not marketing.
- Best mattress for stomach sleepers: the 12-inch Medium, and only the 12. Stomach sleepers need a firmer sleep surface to keep the hips from sinking too deeply and arching the lower back; the 12-inch is the best (and only) fit here. The Medium Plush versions will be too soft.
- Combination sleepers, or sleepers who frequently change position: the 14-inch. It’s plush enough for side sleeping, supportive enough for back sleeping, and the foam response is fast enough that position changes don’t feel like climbing out of a crater. Best all-rounder in the range.
- Hot sleepers and night sweaters: any height. This is the crowd the mattress is built for. If you struggle with heat, end up drenched by morning, or sleep next to a human furnace, the cooling stack is the whole reason to buy this over a cheaper foam mattress. It’s also where pressure relief and cooling finally show up in the same bed.
- Plus-size sleepers: the 12-inch or 14-inch. More body weight means more heat and more pressure, and the firmer build with the high-density base will hold up better over time. Plus-size sleepers who want a plush feel should look at the hybrid instead, where coils carry the weight and the mattress supports you from underneath rather than around you.
- Couples and light sleepers: the motion isolation makes this a strong couples pick as long as neither of you is an edge-sleeper (see above).
- Athletes and active people: the pressure relief is legitimately useful for recovery, the best kind of boring benefit, and the cooling helps if your resting body temperature runs high after training.
SweetNight CoolNest Mattress Review: CoolNest Ultra vs. CoolNest Hybrid vs. Other Mattress Types
SweetNight offers a whole CoolNest family, and the word you’ll see a lot is “hybrid,” so here’s how the Ultra stacks up against the alternatives, including the mattress types SweetNight doesn’t make. Best-case use for each is in the third column.
| Mattress type | What it is | Best for | Trade-off |
| CoolNest Ultra (all-foam) | 7 layers of memory foam and support foam, 5-stage cooling, 7-zone support | Hot sleepers, side sleepers, couples who want motion isolation | Average edge support, Queen/King only for now |
| CoolNest Hybrid | SweetNight’s coil-plus-foam version of the CoolNest cooling system | Sleepers who want bounce and better edge support | Coils transfer a bit more motion than all-foam |
| Generic memory foam mattress | Closed-cell foam, usually one or two layers | Budget buyers who don’t sleep hot | Heat retention; the “foam mattress sauna” problem |
| Latex mattress | Natural or synthetic latex, springy and cool | Eco-minded sleepers who like bounce | Heavy, expensive, less contour than memory foam |
| Organic (wool/latex) build | Wool, cotton, and latex layers | Sleepers prioritizing materials over tech | Often two to three times the price for similar support |
The honest hybrid-versus-foam verdict: hybrid designs win on edge support, bounce, and airflow through the coil layer. All-foam wins on motion isolation, contour, pressure relief, and price. The CoolNest Ultra narrows the airflow gap that usually makes people pick a hybrid mattress for cooling, which is the entire engineering argument for the AirMesh and vented gel layers. If edge support is your deal-breaker, go CoolNest Hybrid. If a partner’s tossing is your deal-breaker, go Ultra.
How to Test the SweetNight CoolNest Without Regret
Buying a mattress online is the one purchase where “I’ll know it when I lie on it” doesn’t work, because you can’t lie on it until it’s already in your bedroom. So use the trial like a grown-up. The best mattress trial is the one you actually run.
- Give it the full 30 nights before you judge. Your body has spent years adapting to your old mattress, sagging and all. A new mattress with real support feels different for a couple of weeks, sometimes in your lower back, before it feels better. SweetNight says 30; we’d say at least 30. Giving the mattress that long is the difference between a fair review and a first impression.
- Test your actual sleep position, not your showroom position. Lie on it the way you sleep at 3 a.m., not the way you’d pose for a catalog.
- Check the edge on purpose. Sit on it. Sleep near it. If it bothers you, you have 100 nights and free pickup.
- Use the right sheets. A cooled-off bed under flannel is one you’ll never feel. Breathable cotton or bamboo lets the Ice Silk cover do its job.
- Support the mattress properly. SweetNight says it works on platform beds, slats, box springs, and adjustable frames; just make sure the foundation is flat and sturdy. Foam on a saggy old box spring is foam that sags, and no quality mattress survives a bad base.
The Rest of the SweetNight Sleep System
Here’s the part where the story stops being about a mattress and starts being about a bed. SweetNight built the CoolNest bedding line on the same cooling fabric family as the mattress cover, and CoolNest’s logic is simple: a cool mattress with a hot comforter on top is only half the problem.
CoolNest Cooling Comforter ($129 Queen, $149 King). A lightweight comforter with a CoolGlide cooling fabric surface (Q-Max 0.4, so it actually feels colder than the mattress cover) and a breathable fill blend of plant-based viscose, Sorona fiber, and airy polyester. It’s machine washable, dryer-friendly, and needs no duvet cover, which is the feature that makes a parent’s eyes go wide. It’s OEKO-TEX certified like the mattress cover. If you’ve been kicking a leg out from under a heavy comforter every night, this is the one that stops the kicking.
CoolNest Ergonomic Cooling Pillow ($79, or $129 for two). Same CoolGlide cooling case, a 420-pod cooling matrix inside, and a dual-height memory foam core (3.1″ and 3.9″ sides) for back and side sleepers. Removable, washable cover. The point is that your head sweats more than the rest of you, and a cool mattress under a hot head is still a hot night.
None of the bedding is required to make the mattress work; there’s no bundle trap, and the CoolNest Ultra mattress can be purchased separately. But if you’re already replacing the mattress because you sleep hot, the comforter is the cheapest second step that makes the first step feel finished.
SHOP:
CoolNest Cooling Comforter | CoolNest Ergonomic Cooling Pillow | CoolNest Ultra Memory Foam Mattress
EXPLORE AND CONNECT:
SweetNight | Facebook | Instagram | X | Youtube | Pinterest
The Verdict: Is the SweetNight CoolNest Mattress Worth It?
I’ll keep the verdict as plain as the takeaway. The SweetNight CoolNest Ultra is a genuinely well-engineered memory foam mattress that solves the one problem memory foam has never solved well: heat. It’s fiberglass-free, certified at every layer, ACA-endorsed for alignment, and backed by a 100-night sleep trial and a 10-year warranty, at a price that starts under $750 for a Queen. For hot sleepers, side sleepers, and couples, it’s the best mattress we’d point to under $1,000, and an easy recommendation. For stomach sleepers and edge-sitters, it’s a “buy the 12-inch” or “look at the hybrid” recommendation, which is still a recommendation.
Is it the perfect mattress? No mattress is.
But it’s a comfortable mattress, a genuine cooling mattress that actively works to keep you cool rather than passively soaking up your body heat, and that’s the difference between waking up rested and waking up in a puddle.
If you’ve been white-knuckling it on an old foam mattress that runs hot, the CoolNest Ultra is worth 30 nights of your time. Better sleep is a low bar when you’re starting from a puddle, and this mattress clears it with room to spare. SweetNight makes it easy to find out; the 100-night trial does the rest. Your 3 a.m. self will notice.
You might also be interested in…
After a great night’s sleep, it’s time to crack your knuckles and referee the Sibling Rivalry Showdown.
CONNECT WITH DAILY MOM
💖 Where every mom deserves a moment. 💖
FIND US ON OUR SOCIALS
LOVE IT? PIN IT!
