Mattresses and Sleeping Hot / Heat Retention

Unbiased Comparison, Analysis Based on 25,503 Owner Experiences

April 12, 2017

What You Need To Know

1. About 8% of people report that their mattress significantly and regularly retains heat and, consequently, sleeps hot. About another 12% say that their mattress sleeps warm but usually not to an uncomfortable degree.

2. Mattress heat retention often results in excessive sweating, restlessness and poor sleep quality.

3. Main factors that affect heat retention include mattress firmness, sleeper weight, mattress type, and comfort layer composition.

4. To combat heat for your current mattress, see temperature control.

Mattress Firmness and Heat Retention

Due to the fact that a person sinks significantly into a softer mattress, air flow around the sleeper is thereby restricted often resulting in greater heat trap potential.

By contrast, a person tends to sleep on top of a firm mattress thereby having greater air flow. However, highly conforming firmer mattresses, such as certain Tempur-Pedic models, have above-average heat trap potential due in part to their ability to strongly contour to the curves of a sleeper's body thereby restricting airflow between the mattress and the sleeper.

mattress firmness heat comparison

Sleeper Weight / Size and Heat Retention

Heavier people tend to have greater potential for sleeping hot. This appears to be due to the fact that a heavy person sinks farther into the mattress where there is less airflow. It may also be due to the fact that a heavier person expends more energy when moving compared to a lighter person and this expenditure creates more body heat.

person weight mattress heat comparison

Heat Retention by Mattress Type

Nearly all mattress types can sleep hot, but some do so more than others. Keep in mind that the following chart represents what is often, but not always, the case. A particular brand, model or individual mattress may go against these findings somewhat.

mattress sleeping hot comparison


About 9% of memory foam mattress owners report sleeping hot to an uncomfortable extent. An additional 15% report their bed being warm but at most times not uncomfortably so. In other words, the clear majority of memory foam mattress owners report no heat problems.

Keep in mind, however, that these numbers may be affected by the fact that memory foam is often known to sleep hot for some people. As a result, people who are naturally hot sleepers may avoid buying a memory foam mattress in the first place – making the rate somewhat lower than it otherwise would be.

Owner experience data suggests that main factors affecting memory foam heat retention – as discussed below – are foam density, foam composition, and cover material.

Memory Foam Density
Memory foam used in memory foam mattresses can have low to high density. Mattresses with high foam density tend to have at least two times the number of reports for bothersome heat retention than do mattresses with low foam density. This appears to be mainly due to high density foam having less open space to allow for air flow. (Learn more about how density affects memory foam mattress characteristics in the memory foam density comparison.)

memory foam density heat comparison

For how specific memory foam mattresses compare in density, see the memory foam mattress reviews - summary.

Gel-Infused Memory Foam
Many memory foam mattresses use memory foam infused with millions of gel beads. This gel-infused foam is designed to sleep cooler longer than regular memory foam. Owner experience data shows it to reduce heat-trap complaints significantly for all memory foam densities – by as much as 30%. Nevertheless, about 6% of gel memory foam bed owners still find gel-infused foam to sleep hot.

gel memory foam vs non

Cover Material

Several memory foam mattresses use a moisture-wicking cover such as a Coolmax® or Outlast® fabric. The material is designed to let perspiration quickly evaporate allowing for cooler sleep. Owner experience data suggests that such a cover is often at least somewhat effective at reducing heat problems.

coolmax vs non chart


Hybrid mattresses are spring-based mattresses with at least two inches of memory foam in the comfort layer. About 12% of owners report sleeping hot – a higher than average rate due likely due to the presence of the memory foam. An additional 20% report above average warmth but not to a bothersome extent most of the time.


Latex mattresses are second only to memory foam / hybrid mattresses for having the most complaints regarding heat buildup. Most complaints, however, are for all-latex beds as opposed to latex-hybrids.

latex mattress heat comparison


Airbeds with a three-inch or thicker comfort layer have nearly twice the likelihood of retaining heat to a bothersome extent than those models with a less-thick layer. Three-inch thick or thicker comfort layers in some cases consist partly or entirely of memory foam.

air bed heat comparison


Innerspring mattresses – especially medium to firm models without memory foam or latex – have relatively few heat-related complaints.


Waterbeds do not have a significant sleeping hot issue because the water inside keeps the temperature down. In fact, if the beds do not have a heater to warm the water, there may be a sleeping cold issue especially in cooler climates and during winter months.


Sleeping hot does not tend to be a noteworthy problem for futon mattresses. Models with memory foam likely sleep hotter than those models without.

Sleep Like The Dead's mattress research in The News –

About our unbiased mattress research

Findings are based on over 25,500 mattress owner experiences collected from diverse and credible sources. Learn more about our mattress research methodology and sources.





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