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Sleeping hot is an issue for roughly 1 in 10 adults, and excessive warmth during the night can lead to poor sleep quality and feelings of tiredness the next day. People who sleep hot require more cooling than other sleepers. Some mattresses retain very little body heat, and tend to sleep relatively cool. Others absorb and trap heat, and often sleep hot as a result. Although some mattress types are associated with sleeping hotter or cooler than others, there are other factors that affect temperature neutrality in mattresses. These include mattress firmness and comfort layer materials, as well as the sleeper’s body weight and bedroom settings.
This guide will look at the best and worst mattresses for sleeping hot, and also look at strategies and products that can help ensure you maintain a comfortable temperature throughout the night.
Arguably the two factors that have the biggest impact on sleeping hot or cool are mattress firmness and the sleeper’s bodyweight.
Firmness is normally rated on a 1-to-10 scale, with 1 being the softest and 10 being the firmest, but most mattresses sold today fall between a 3 (Soft) and an 8 (Firm). Mattresses rated below a 5, or Medium, tend to sink beneath a sleeper’s body to create a cradle-shaped impression. While this type of sleep surface has noted benefits — such as motion isolation and pressure relief — the deep conforming can create a heat trap and restrict air circulation. Mattresses rated between a 6 (Medium Firm) and an 8 do not conform as deeply and, as a result, usually sleep much cooler than their less-firm counterparts.
Sleeper bodyweight is important because heavier people tend to emit more body heat and sleep warmer compared to lighter people. There are two reasons for this. One, heavier people sink further into the mattress than lighter people, often resulting in a heat trap. Secondly, heavier people must use up more energy to move in bed, and this can drive up their body temperature.
The bottom line: anyone who tends to sleep hot — especially people who weigh more than 200 pounds — will probably feel most comfortable on a mattress rated at a 6 or higher on the firmness scale.
Various components in the comfort layer and support core of a mattress will affect how hot or cool the bed sleeps. These components include:
Steel Coils and Springs: 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.
Latex: 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.
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.
Airbeds: 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.
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.
Regular Memory Foam: Memory foam can be quite problematic for people who sleep hot, and roughly 10% of mattress owners claim this material negatively affects their sleep. 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.
The table below rates each of these materials in terms of sleeping hot.
|Mattress Material||‘Sleeping Hot’ Rating|
|Springs and Coils||Very Good to Excellent|
|Latex||Good to Very Good|
|Advanced Polyfoam||Fair to Good|
|Open-cell memory Foam||Fair to Good|
|Regular Memory Foam||Poor|
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 also 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 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.
For more information on phase-change materials, check out the website for Outlast, the premier PCM used in mattress covers made today.
Cooling Fabrics: Some mattress are advertised with covers made from ‘cooling fabrics’, such as:
Now that we’ve discussed comfort layer, support core, and cover materials that affect mattress temperature, let’s look at a few bedding options and bedroom accessories that may help you stay cool and comfortable 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 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, as well as synthetics like imitation down, memory foam, and polyester. The table below compares eight common pillow materials based on how cool they sleep.
|Pillow Material||‘Sleeping Cool’ Score|
|Buckwheat||Good to Very Good|
|Down||Good to Very Good|
|Down Alternative (Imitation)||Good to Very Good|
|Feathers||Good to Very Good|
|Latex||Good to Very Good|
|Memory Foam||Poor to Fair|
|Natural/Organic Fibers (Cotton, Silk, Wool, etc.)||Good to Very Good|
|Polyester||Fair to Good|
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.
Climate Control System: 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 Wink Beds 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.
Climate control systems can be quite effective at helping sleepers stay cool, but there is a major downside: the price-tag. The BedJet starts at $269, while the Wink Beds coolControl™ base will add a $2,200 surcharge to the mattress price. Simply put, there are less expensive ways to help you sleep at a comfortable temperature.
Many mattress manufacturers offer sleep trials, during which time the purchaser can test out their new mattress to ensure it will meet their needs and preferences. Most sleep trials span 60 to 120 nights; if the purchaser is dissatisfied with their new mattress, then they will be able to return and/or exchange it for a product refund.
If you sleep hot, then a mattress sleep trial can prevent you from committing to a mattress that will make you uncomfortable. The costs associated with most sleep trials are minimal. Some manufacturers require the mattress buyer to cover shipping and handling costs associated with returns or exchanges, while others will handle these expenses. In most cases, a full product refund will be issued to those who return their mattress before the sleep trial ends.
In terms of warranty coverage, it’s important to note that most — if not all — mattress warranties will not cover issues pertaining to owner comfort preferences, including sleeping hot. So if you purchase a mattress that sleeps hot but do not return it during the sleep trial, then there is a strong chance you will not be able to return or exchange the mattress for a full, or even partial, refund.
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 mattress or bedding accessories: