It is 3 a.m., and you have flipped the pillow to the cool side for the fourth time tonight. If you keep waking up warm and sticky, the problem usually is not you. It is the heat trapped between your body and the surface you are lying on. The good news: learning how to keep a mattress cool rarely starts with buying anything. This guide ranks seven fixes from free to upgrade, so you spend money only after the cheap fixes run out. You will learn exactly which steps move the needle, which ones are a waste, and how to choose a sleep surface built to stay cool if it comes to that.
The Quick Answer: The Cooling Ladder
To keep a mattress cool, start at the cheapest rung and climb only if you are still hot:
- Rung 1 (free): Drop the room to 60–67°F
- Rung 2 (free): Lighten your sleepwear and bedding
- Rung 3 (low cost): Switch to breathable cotton, linen, or bamboo sheets
- Rung 4 (low cost): Run a fan
- Rung 5 (low cost): Add airflow underneath with a slatted base
- Rung 6 (moderate cost): Add a gel or phase-change cooling topper
- Rung 7 (highest cost): Upgrade to a mattress built to sleep cool
Why Does a Mattress Get So Hot?
A mattress gets hot when heat from your body has nowhere to go. Your body sheds warmth all night, and if that heat cannot disperse into the air or escape beneath the bed, it builds up at the surface and radiates straight back at you. Three culprits cause most of it: dense foam with little ventilation, a solid base that blocks airflow underneath, and synthetic sheets that hold warmth in.
Memory foam has a reputation for sleeping warm for a reason. Its density makes it less breathable, and its body-hugging contour wraps around you, which reduces the open space where air would normally carry heat away. According to the Sleep Foundation, some pillow and mattress materials, including memory foam, can trap heat that feels uncomfortable for warm sleepers.
The fix is not always a new mattress. In practice, many heat complaints come down to airflow and bedding, not the mattress itself. That is why the order you tackle this in matters more than the products you buy.
The Cooling Ladder: 7 Fixes Ranked From Free to Upgrade
We call this the Cooling Ladder. The idea is simple: work from the bottom rung up, and stop as soon as you are comfortable. Many people never need the top rungs. Climbing in order means you never overpay to solve a problem a free fix would have handled.
1. Drop Your Bedroom to 60–67°F (Free)
The single most effective change costs nothing. Sleep researchers generally point to a bedroom temperature between 60 and 67 degrees Fahrenheit as the sweet spot. A warm room forces your mattress to soak up ambient heat on top of your body heat, so cooling the room cools the bed by extension. Set the thermostat, crack a window, or run the AC an hour before bed. For light, sound, and texture as well as temperature, see our sensory-friendly bedroom guide.
2. Lighten Your Sleepwear and Bedding (Free)
Heavy pajamas and stacked blankets can undo every other fix on this list. Strip down to one breathable layer in warm months, and you remove a significant heat source before spending anything.
3. Switch to Breathable Sheets (Low Cost)
Your sheets sit between you and the mattress. Cotton, linen, or bamboo with a lower thread count lets heat escape — polyester and microfiber hold it in. It is a quick swap if you have not made it already.
4. Run a Fan (Low Cost)
Moving air carries heat away faster than still air. A ceiling or pedestal fan works well for most people. If you sweat heavily or have hot flashes, a forced-air or water-based bed-cooling system goes further: it actively chills the surface, though it costs considerably more than a fan.
5. Add Airflow Underneath With a Slatted Base (Low Cost)
This is the fix most people skip, and it is one of the best. A slatted bed base lets air circulate beneath the mattress so warm, moist air escapes instead of pooling underneath. A solid platform or a mattress on the floor traps that heat. Aim for slats spaced two to three inches apart. If your frame is solid, even a slatted bunkie board or bed risers for ground clearance will help.
6. Add a Cooling Topper (Moderate Cost)
If the first five rungs are not enough, a gel or phase-change topper pulls heat from the surface for the first few hours. Treat it as a surface fix — it cannot address heat trapped deep in the foam or a mattress that is already sagging.
7. Upgrade to a Mattress Built to Sleep Cool (Highest Cost)
If you have climbed every rung and still sleep hot, the mattress itself is the bottleneck. A sleep surface built with cooling materials — gel-infused foam, copper-infused covers, or phase-change layers — can address heat deeper in the bed, where a topper only works at the surface. This is the last rung for a reason: it is the priciest, and many people fix their heat problem before they reach it. When you do need it, look at our full mattress collection and filter for the cooling models.
Cooling Mattress Topper vs. a Cooling Mattress: Which Is Worth It?
A cooling topper is the right call when your mattress is otherwise comfortable and only the surface runs warm. A cooling mattress is the right call when the bed traps heat in its core, sags, or is already near the end of its life. Here is how they compare on the factors that matter.
| Factor | Cooling Topper | Cooling Mattress |
|---|---|---|
| Upfront cost | Lower | Higher |
| When it helps most | Early in the night, before it warms up | Through the night, by limiting heat buildup |
| Helps with heat held deep in the bed | No | Yes, if the core breathes (coils or latex) |
| Adds support | Minimal | Yes |
| Best for | A good mattress that runs warm | An old or heat-trapping mattress |
| Lifespan | Shorter | Longer |
The honest answer: if your mattress is under five years old and supportive, start with a topper. If it sags or you wake up warm no matter what you try, a topper is money spent twice — put it toward a mattress that sleeps cool from the inside out.
What Makes a Mattress Sleep Cool?
A mattress sleeps cooler when its materials let heat move away from your body instead of trapping it. Regular memory foam is dense, with small, tightly packed cells, so body heat tends to build at the surface. Mattresses designed to sleep cooler use different layers to reduce that buildup. Here is how each one works.
Gel-Infused Foam
Gel beads or a gel swirl embedded in foam increase its thermal mass — the foam absorbs the heat you generate and distributes it through the layer rather than letting it concentrate at your skin. The Ground Pro™ uses this kind of cooling gel memory foam as its top comfort layer.
Latex Foam
Latex has a naturally open-cell structure, meaning the foam itself is full of tiny interconnected air pockets and it is less dense than memory foam. Many latex layers are also pin-cored — small vertical channels are punched through the foam — which creates direct air pathways. Every time you shift position, air moves through those channels and carries heat away. Latex also does not contour tightly around your body the way memory foam does, so more air can move between the foam and your skin. This is why latex generally sleeps cooler than standard memory foam.
Copper-Infused Materials
Copper conducts heat much better than foam, which is why some mattress makers add it to covers and comfort layers. Copper-infused fabrics and foams are designed to help draw warmth away from your skin and spread it out, rather than letting it build up at the surface. Our Attune™ and Attune Pro™ both use copper-infused covers for this reason.
Phase-Change Materials (PCM)
Phase-change materials are engineered to absorb large amounts of heat as they transition between states — similar to how ice absorbs heat as it melts. As a PCM layer warms toward body temperature, it soaks up heat from the surface, and it releases that heat later as it cools. This can keep the surface feeling steadier for longer than a simple gel layer, but its capacity is limited: once it has absorbed all the heat it can hold, it warms up like any other material.
Here is how the Sleepy Edge mattresses apply these technologies and who each one is built for:
| Mattress | Cooling Technology | Best For |
|---|---|---|
| Ground Pro™ | Cooling gel memory foam + breathable stretch-knit cover | Hot sleepers who want a firm all-foam feel |
| Attune Pro™ | Copper-infused cover + bio-based memory foam | Warm sleepers who want a medium-firm, contouring feel that still sleeps cool |
| Attune™ | Copper-infused breathable cover | Side sleepers who run warm and want targeted pressure relief |
For hot sleepers who like a firm feel, the Ground Pro™ pairs a cooling gel memory foam layer with a breathable stretch-knit cover. For a more contouring feel, the Attune Pro™ has a copper-infused cooling cover over its comfort layers. Every Sleepy Edge model uses CertiPUR-US certified foams and ships with a 120-night sleep trial so you can test how cool it sleeps in your own bedroom before committing.
How to Keep a Memory Foam Mattress Cool
Memory foam runs warm because it is dense and wraps around you, but you can cool it down without replacing it. Work through these steps in order:
- Lower the room to 60–67°F so the foam is not absorbing extra heat from the air.
- Move the mattress onto a slatted base so air circulates beneath the foam and warm air escapes.
- Add a gel or phase-change topper to put a breathable layer between you and the dense foam.
- Switch to cotton, linen, or bamboo sheets and drop the thread count for a more open weave.
- Run a fan to keep air moving across the surface all night.
In practice, the slatted base and the room temperature do most of the work. If you have done all five and still wake up hot, the foam itself is holding heat, and that is the signal to look at a mattress with cooling materials built in.
The Bottom Line
Many heat problems can be solved on the lower rungs — a cooler room, breathable sheets, and airflow under the bed — long before you need to spend on a topper or a new mattress. Climb the ladder in order and stop when you are comfortable. If you reach the top rung, the Ground Pro™ pairs cooling gel memory foam with a breathable stretch-knit cover.
Shop the Ground Pro™ →Frequently Asked Questions
Why does my mattress get so hot at night?
A mattress feels hot when heat from your body has nowhere to escape. Dense foam without ventilation, a solid bed base that blocks airflow underneath, and synthetic sheets that trap warmth all combine to hold heat against your skin instead of letting it disperse into the room.
Do cooling mattress toppers really work?
Yes, a quality cooling topper helps, but it is a partial fix. Gel-infused foam and phase-change toppers pull heat away from the surface for a few hours. They cannot fix a mattress that traps heat in its deeper layers, so a topper works best alongside a slatted base and breathable bedding.
Does a slatted bed frame keep a mattress cooler?
Yes. A slatted base lets air circulate beneath the mattress so warm, moist air can escape rather than pool underneath. A solid platform or box without gaps traps that heat. Switching to slats spaced two to three inches apart is one of the cheapest ways to keep a mattress cool.
What is the best mattress for hot sleepers?
The best mattress for hot sleepers uses cooling materials such as gel-infused foam, copper-infused covers, or phase-change layers, paired with a breathable, open construction. The Sleepy Edge Ground Pro™ has a cooling gel memory foam layer under a breathable stretch-knit cover, and the Attune Pro™ uses copper-infused cooling for warmer rooms.
What temperature should my bedroom be for sleep?
Sleep researchers generally recommend a bedroom temperature between 60 and 67 degrees Fahrenheit. A cooler room helps your body settle in for the night and stops your mattress from absorbing extra warmth from the air around it. It is the first and cheapest fix to try.
How do I make a memory foam mattress cooler without buying anything?
Lower your bedroom to 60–67 degrees, pull back heavy blankets, run a fan for airflow, and lift the mattress onto a slatted base if you have one. These free or near-free steps often solve heat complaints before you spend a cent on toppers or a new mattress.
