Which Types of Mattresses Sleep Hot vs. Cool?
Various components in the comfort layer and support core of a mattress will affect how hot or cool the bed sleeps. Below we review the most popular types of mattresses available today, and how well (or not) they regulate temperature for hot sleepers.
Innersprings are generally regarded as the coolest mattress options because they absorb a small amount of body heat and usually do not sleep warm. This is largely due to their support cores, which are constructed with steel springs and coils that are evenly spaced to provide sleeper support and equal weight distribution. Air circulates in the spaces between these metal parts, which helps the mattress stay cool. Exceptions to this rule are hybrids and innersprings with thick foam comfort layers, which may sleep hotter than those with thin comfort layers.
Given that they’re made entirely of foam, all-foam mattresses conform closely to the body and tend to fall on the softer side, firmness-wise, both of which can result in trapped body heat and an uncomfortably warm sleep experience. However, these mattresses can sleep sufficiently cool for hot sleepers, allowing them to enjoy conforming pressure-relief without the heat. It all depends on the types of foams used in the mattress.
Gel-infused Foam: Many mattress manufacturers tout models with ‘gel-infused memory foam‘ as sleeping much cooler than mattresses made from standard memory foam. This is a reasonable argument, since gel must absorb a certain amount of body heat before its temperature will change. However, owner experiences with gel-infused foam mattresses are fairly mixed, and some say they retain as much body heat as standard foams. The key distinction here is how much gel is infused into the foam; foams with a high gel concentration tend to sleep cooler than those with lower concentrations. Other foams may feature beads or other trace gel components, but these materials have little — if any — effect on the foam’s body heat retention.
Other Specialty Foams: In addition to gel foams, specialty foams may be infused with other materials like copper or graphite. And similarly, the cooling properties of these foams will depend on the concentration of copper, graphite, or other specialty materials.
Regular Memory Foam: Memory foam can be quite problematic for people who sleep hot. Memory foam responds to temperature changes by conforming to the sleeper’s body, which can create a heat trap. Additionally, many memory foam mattresses feature support cores made from high-density polyfoam, another material known to sleep hot.
Advanced Polyfoam: Some advanced polyfoams are designed to regulate temperature more effectively than regular polyfoam, but owner experiences have been somewhat mixed and advanced polyfoam is generally not recommended for people who usually sleep hot.
Open-cell Memory Foam: While memory foam is regarded as the hottest mattress material available, open-cell memory foam may sleep somewhat cooler because of improved air circulation.
Regular Polyfoam: Polyfoam is generally cooler than memory foam due to its open-cell structure and relatively low density, but it tends to sleep warmer than materials like latex. One contributing factor to the above-average warmth is the support core, which is often made from high-density polyfoam. Mattresses that feature convoluted polyfoam in the comfort layer may sleep cooler due to air channels that form between the grooves in individual layers.
Hybrid mattresses are, appropriately, a hybrid of innerspring and foam mattresses. These mattresses combine a coil-based support core with several inches of foam or latex in the comfort layers. Hybrid mattresses use pocketed coils in their support core, enhancing the overall contouring capability of the mattress while still allowing ample airflow.
The suitability of a hybrid mattress for hot sleepers depends largely on the materials used in their comfort layers and cover. Hybrid mattresses that feature latex or gel-infused memory foams, like The DreamCloud and WinkBed Plus, will sleep cooler than those with memory foam. Covers made of breathable cotton — or better yet, infused with cooling copper, like the Aurora — are also ideal.
Latex mattresses feature at least one layer of latex in the comfort layer, and may also have latex-based support cores. Unlike polyfoam or memory foam, latex does not absorb much body heat or respond to temperature changes. Latex layers are often perforated, which can promote better air circulation. However, latex that is blended or entirely synthetic may not sleep as cool as natural latex.
Airbeds feature air chambers in the support core that can be adjusted to change the firmness of the mattress. The comfort layer is typically made from polyfoam or memory foam, and how hot or cool they sleep often depends on comfort layer thickness. Generally speaking, comfort layers that are more than 3? to 4? thick sleep significantly hotter than thinner comfort layers.
Many mattresses will feature several of these materials. For example, an innerspring mattress may include memory foam in the comfort layers, while a hybrid mattress may have layers of both latex and memory foam. The table below rates each of these mattress materials and their ability to help you sleep cool.
How Does the Mattress Cover Affect the Mattress Temperature?
In addition to materials found in the comfort layer and support core, the mattress cover can also affect body heat retention and temperature regulation. Let’s look at four common cover materials and how they rate in terms of sleeping hot or cool.
Non-quilted Covers
Non-quilted covers tend to be the thinnest. The thinner the cover, the better the air circulation. As a result, non-quilted covers often sleep cooler than other cover options.
Quilted Covers
Quilted covers are thicker than non-quilted covers, which means the air circulation may not be as good. Additionally, many quilted covers feature thin layers of polyfoam or memory foam that can affect the sleep surface temperature.
Phase-Change Materials
‘Phase-change materials’, or PCMs, refers to materials that are designed to retain body heat until the sleeper’s body reaches a certain temperature, at which point it will stop absorbing heat. This allows phase-change covers, like those found in the Muse Mattress and Aurora, to maintain a steady, moderately cool temperature regardless of how much body heat the sleeper is emitting. Phase-change material may not sleep as cool as a non-quilted cover, but many mattress owners claim these materials effectively keep the heat down throughout the night.
Cooling Fabrics
Some mattresses are advertised with covers made from ‘cooling fabrics’, such as:
- Celliant® Fibers: Celliant® fibers are produced using thermoreactive minerals that help improve circulation in sleepers and regulate their body temperature throughout the night. These covers tend to sleep fairly cool, but some mattress owners still report sleeping hot.
- Lyocell: Lyocell is a type of rayon made of cellulose, a material from wood pulp. It is relatively thin and lightweight, and may provide a suitably cool surface for hot sleepers. The WinkBed Plus, our favorite mattress for heavier hot sleepers, features a lyocell cover.
- Lycra® Spandex: This material is highly elastic and often found in athletic clothing, as well as bras and underwear. It also wicks away moisture, which can be beneficial for people who sweat due to sleeping hot.
Cooling Pillows, Bedding, & Sleep Accessories for Hot Sleepers
Now that we’ve discussed the best cooling mattresses, let’s look at a few bedding options and bedroom accessories that can help you stay even cooler while you sleep.
Sheets
As many people have seen firsthand, the options for bedsheets are seemingly endless. Sheet options fall into one of two general categories: natural fibers or synthetic materials. Natural fibers used in sheets include:
Natural fibers tend to be softer and more breathable than other cover fabrics, which can help regulate temperature and maintain a cool sleep surface. Long-staple cotton and linen are considered exceptionally cool. Additionally, wool naturally wicks away moisture; it also sleeps warmer or cooler depending on the room temperature, making wool sheets a good choice for year-round temperature regulation.
The most common synthetic fabrics used in sheets are polyester and rayon. These are not as breathable as natural fibers and will sleep warm by comparison, although certain synthetics — such as polyester microfibers — are able to wick away moisture, which can help lower the sleeper’s body temperature.
Some sheet fabrics may be all-natural or blended natural-and-synthetic. For example, bamboo viscose is made from cellulose and bamboo fabric, and may or may not contain chemical ingredients. These fabrics often sleep cool, but in most cases natural-fiber sheets will sleep somewhat cooler.
Mattress Toppers
A mattress topper is used to provide an extra inch or two of cushioning to the comfort layer, and is usually purchased separately from the mattress itself. These are different from mattress pads, which are primarily used to protect the mattress.
Not surprisingly, memory foam toppers tend to sleep the hottest. Toppers made from fabric/fibers or latex also absorb body heat to a fair extent. The coolest topper options include feather toppers (also known as featherbeds) and toppers made from wool.
Pillows
Pillows sold today are crafted from a wide range of materials, including natural fibers like buckwheat, down or feathers, cotton, wool, and silk. These sleep significantly cooler than synthetic materials like down alternative, memory foam, and polyester.
The table below compares eight common pillow materials based on how cool they sleep.
Sleepwear
Like all the other things your body comes into contact with throughout the night, sleepwear is an important factor in how cool you’ll be. Like bedding products, how temperature neutral your sleepwear is mostly depends on the material it’s made out of. Linen and bamboo sleepwear are among the coolest materials, with cotton being fairly cool as well. If you sleep hot, make sure to avoid flannel or polyester pajamas. Additionally, you can always sleep naked.
Bedroom Fans
Fans improve airflow throughout the bedroom and can help sleepers stay cool, particularly during hotter times of the year. Some louder models may cause sleep disruption, although some sleepers find the background noise is conducive to sleep. Ceiling fans may also be suitable, although some mattresses may be too low to the ground to have a noticeable effect.
Mattress Climate Control Systems
In addition to fans, some products can be used to regulate mattress temperature by releasing cool or warm air into the bed. These systems can be useful for individuals who sleep excessively hot or those who tend to get too cold during the night.
One example is the BedJet, an accessory that releases currents of convective air onto both sides of the mattress using a hose attachment. Owners can adjust the air settings to find the right temperature, and the BedJet is capable of releasing warm and cool to opposite sides of the bed for couples who have different sleep preferences.
In addition to accessories, some mattress bases also provide climate control. Take the WinkBeds coolControl™, a base equipped with four air tubes that fit into the bottom of the mattress and supply currents of air that rise to the top surface. Using a smart app, owners can adjust the settings until they reach a suitable temperature.
Cooling Mattress Buying Tips for Hot Sleepers
If you and/or your sleep partner tend to sleep hot, be sure to keep the following points in mind when shopping for a new cooling mattress or bedding accessories.
