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As a hot sleeper, my search for the perfect mattress has taught me that the cooling-mattress market has never been more crowded.
The challenge is that many of these products use completely different technologies while making very similar claims.
Today, let’s take a closer look at two products on opposite ends of that divide: Amerisleep’s cooling mattresses, which rely on passive materials like their plant-based Bio-Pur® foam, and the Eight Sleep Pod Cover, an active system that circulates water through a bedside hub to heat or cool each side of the bed independently.
Understanding how these two approaches actually work is the first step to figuring out which one (or whether either one) is worth it for your specific situation.
Passive vs Active Cooling
Let’s first talk about what each of these brands is claiming that they do by discussing the differences between passive and active cooling.
Passive Cooling
Passive cooling materials don’t remove heat from the system at all. They redistribute it, or slow down how quickly it builds up against your skin. Active cooling systems physically transport heat away from the bed using water or air circulation, a mechanically different process with a different ceiling on performance.
Materials like gel-infused foam, graphite, phase-change compounds, and open-cell foams either conduct heat away from your body faster than standard foam, or absorb heat as you sleep and hold it, delaying the point where you start to feel warm.
Phase-change materials in particular work by literally changing state as they absorb body heat, similar to how an ice pack stays cold by melting rather than by “actively” refrigerating anything. That’s a real upgrade over standard memory foam, which traps heat almost by design, but it comes with a functional limit: once the material has absorbed as much heat as it can hold, its cooling effect saturates and performance drops off for the rest of the night.
Active Cooling
Active systems sidestep that ceiling by continuously cycling water or air rather than relying on a material’s fixed heat capacity. A hub pulls heat away from (or adds heat to) the sleep surface for as long as it’s running, adjusting in real time to inputs like body temperature, sleep stage, and room conditions.
That’s the actual meaning behind the “active” label: not a stronger version of what a gel-infused foam is doing, but a different mechanism entirely, closer to a small refrigeration loop than to a material that happens to feel cool to the touch.
Amerisleep and Passive Cooling in Practice
Amerisleep is one of the better examples of passive cooling done right. Rather than relying on electronics or active temperature regulation, Amerisleep focuses on improving the mattress itself to create a more comfortable sleep environment. Its cooling line combines breathable foam with a Refresh Cooling Cover to minimize heat buildup without requiring electronics or ongoing maintenance. If you sleep warm at night but don’t regularly wake up overheated, this may be all you need.
Amerisleep’s current most popular all-around model is the AS3, available in both all-foam and hybrid versions. It is also the company’s best selling mattress and includes the latest cooling features across the lineup.
According to Amerisleep, the AS3 combines:
- Bio-Pur open-cell memory foam for greater airflow than traditional memory foam
- The Refresh Cooling Cover, designed to feel cool to the touch and transfer heat away from the sleeper
- Zoned HIVE support for pressure relief and spinal alignment
Amerisleep says the Refresh Cover maintains a sleep surface averaging about seven degrees cooler than a standard polyester cover over an eight hour sleep period, while the Bio-pur foam’s open-cell structure allows warm air to escape more easily than conventional memory foam. The Bio-Pur foam is also more breathable than traditional dense memory foam, while the Refresh Cover is engineered to pull heat away from the body when you first lie down.
To put it more plainly: Amerisleep improves temperature regulation by making the mattress itself less likely to trap heat. This passive cooling method works well when your body naturally regulates temperature but you’d like less heat buildup.
While its cooling features get much of the attention, the AS3 is ultimately designed to be a comfortable, supportive mattress. Its medium feel makes it a versatile option for many sleep positions, and the zoned HIVE support system is intended to provide extra pressure relief around the shoulders and hips while keeping the spine aligned. If you’re shopping primarily for a high-quality mattress that also happens to sleep cooler than average, Amerisleep makes a compelling case.
As I continued researching, I realized there was a limit to what passive cooling could accomplish. No matter how breathable the foam or how advanced the cooling cover, the mattress itself isn’t actively changing temperature. As someone who regularly wakes up hot and throws off blankets in the middle of the night, I wasn’t sure that reducing heat buildup would be enough.
Eight Sleep and Active Cooling in Practice
Unlike traditional cooling mattresses, the Eight Sleep Pod Cover doesn’t rely on breathable foams or cooling fabrics to manage heat. Instead, it uses a network of thin, water-filled channels woven into the cover that sits on top of your existing mattress.
Those channels are connected to a small hub beside the bed, which heats or cools the water to your preferred temperature. Rather than helping excess body heat escape, the system actively regulates the temperature of the sleep surface and can make adjustments throughout the night as your body temperature naturally changes. Because it’s powered by circulating water instead of passive materials, its performance is far less dependent on your bedroom’s ambient temperature.
One of the features that immediately stood out to me was Eight Sleep’s dual-zone cooling. This means that each side of the bed can have a different temperature. Both sides adjust independently, so if your partner sleeps at a hotter temperature than you, their side will adjust accordingly without disrupting your sleep.
Because it is a smart sleep system, the Eight Sleep Pod Cover can automatically change through the night. It doesn’t just stay one temperature, and will learn your preferences over time. For example, if you like to stay extra cool while falling asleep but prefer waking up in a warm bed, the cover can slowly warm toward morning.
Temperature regulation was a huge factor for me in my search for the perfect mattress, but I found that was only part of what the Eight Sleep Pod Cover offers. This smart sleep system also tracks metrics like sleep stages, heart rate, heart rate variability, and respiratory rate without requiring you to wear a smartwatch or fitness tracker. This was a big deal to me as I like to be able to track my sleep, but hate wearing a bulky watch or ring to bed.
Through the Eight Sleep app, you can review your nightly sleep data and receive insights into how well you recovered, making it appealing for someone like me who likes to monitor their health and performance.
Should You Add an Eight Sleep Pod Cover to an Amerisleep Mattress?
The more I researched, the more I realized I didn’t necessarily have to choose between the two. Amerisleep provides the foundation: a comfortable, supportive mattress that sleeps cooler than traditional memory foam.
Eight Sleep adds a layer of technology designed to actively regulate temperature and track your sleep. Rather than replacing what makes a good mattress comfortable, the Pod Cover enhances it. That’s why I stopped thinking of them as competitors and started thinking of them as products that could work together.
Of course, adding an active sleep system comes with a much higher investment than purchasing a cooling mattress alone. For many shoppers, the biggest question isn’t whether Eight Sleep works, but whether the additional cost is worth the upgrade.
Amerisleep’s biggest advantage is its simplicity. Once you purchase the mattress, there are no additional costs, no electronics to maintain, and no subscription to manage. It delivers a cooler sleep surface through its materials and construction alone. Eight Sleep, however, represents a different type of purchase. You’re not just buying a cooler layer for your mattress, you’re investing in a connected sleep system that includes temperature control, sleep tracking, and personalized adjustments. That added technology comes with a higher upfront cost and a membership for advanced features.
The Cost Difference: Is Eight Sleep Worth The Upgrade?
The biggest factor that separates these two options is the investment. Amerisleep represents a traditional mattress purchase: you pay for the mattress upfront and the cooling features are built directly into the materials.
The AS3, the model compared throughout this article, has a regular starting price of around $1,700 for a queen size mattress, although Amerisleep frequently runs promotions that may significantly reduce the price. The final cost also varies depending on the mattress size and whether you choose the all-foam or hybrid version.
Eight Sleep is a different category of product. The Pod Cover adds active temperature regulation, sleep tracking, and automation to your existing mattress, but that technology comes with a higher upfront cost.
Depending on the model, mattress size, and current promotions, the Eight Sleep Pod Cover generally starts in the mid-$2,000 range, with an additional membership required for many advanced smart features.
For some shoppers, that extra expense may feel unnecessary. For others, especially those who view temperature control as the key to better sleep, it may be exactly what they have been looking for.
Which One Is Right For You?
Ultimately, choosing between Amerisleep and Eight Sleep comes down to whether you want a mattress that sleeps cooler or a sleep system that actively controls your sleep environment. Both approaches can be effective, but they are designed for different types of sleepers.
Choose Amerisleep If:
- You sleep warm but don’t regularly wake up overheated
- You want a premium mattress without technology
- You don’t want subscriptions
- You value simplicity
Choose Eight Sleep If:
- You consistently wake up hot
- You and your partner prefer different temperatures
- You like tracking your sleep data
- You want automatic temperature adjustments
For many people, Amerisleep’s passive cooling approach will be more than enough. A well-designed mattress with breathable materials can make a noticeable difference if your main issue is heat retention from traditional memory foam. However, for sleepers who feel like they have already tried everything, from sleeping with fewer blankets, lowering the thermostat, or constantly searching for the cool side of the pillow, the ability to actively control temperature can be a major upgrade.
Is Passive Cooling Enough?
When I started researching cooling mattresses, I assumed I was looking for the mattress that stayed the coolest. What I learned was that there is a major difference between reducing heat buildup and actively controlling temperature.
Amerisleep does an excellent job at the first. The AS3 is a comfortable, supportive mattress that uses thoughtful materials to improve airflow and reduce the heat retention associated with traditional memory foam. For many sleepers, that will be all they need.
But as someone who regularly sleeps hot, I realized I was looking for something beyond a cooler mattress. I wanted a system that could adapt to my body throughout the night rather than relying on materials to manage heat. That’s where Eight Sleep stands apart.
The Pod Cover is more expensive and comes with the added complexity of a smart sleep system, but it offers something passive cooling cannot: active temperature control, personalized adjustments, and biometric insights.
The deciding factor for me was that I wasn’t just looking for a mattress that trapped less heat, I was looking for a sleep environment that could actively respond when my body temperature changed. I also liked that this gave me the option of sticking with my current mattress and focusing on putting my money towards investing in better sleep technology.
For shoppers who are serious about staying cool, especially couples with different temperature preferences, Eight Sleep earns its place as a premium upgrade.