What is copper in a mattress and does your cooling mattress need it?

(Image credit: Zoma)

As mattress manufacturers turn to innovative cooling solutions to help the 57% of Americans who run hot at night sleep better, graphite is becoming a popular mattress materials.

With high thermal conductivity and natural fire retardant properties, there's a strong case for infusing mattresses with graphite. Many of the best mattresses we've tested feature added temperature regulation, and brands such as Saatva, athlete-endorsed Zoma and organic Avocado all use graphite for cooling.

But how exactly does graphite work in mattresses and do all the best cooling mattresses need it? Let's take a look...

What is graphite in mattresses?

In mattresses, graphite is used as a thermal conductor and natural flame retardant, helping dissipate heat, regulate temperature and generally provide a more comfortable, safer sleep environment.

Graphite ribbons or powder can be woven into mattress foams or added as a separate layer. Any graphite layers need to sit near the top of the mattress, to effectively draw heat away from the body and disperse it.

A woman laying on Saatva graphite mattress topper on thick white mattress in light bedrrom with big windows looking out to greenery, wooden bedside table and lamps — (Image credit: Saatva)

Besides climate control, graphite is also used as a naturally derived fire barrier. with an impressive safety rating (alternative retardant fiberglass comes with health risks.)

When in contact with fire, graphite expands and absorbs oxygen. By removing the oxygen from the fire, graphite prevents burning.

How does graphite keep you cool?

Graphite is a natural mineral with high thermal conductivity properties, meaning it can take in heat from the body and send it elsewhere.

When it senses heat, graphite absorbs this warmth before conducting it towards cooler areas of the mattress. This balances temperature across your sleep surface to prevent overheating in certain areas.

A hand pressing into white surface of Nectar Classic memory foam mattress — (Image credit: Future)

Due to the density of the material, memory foam has a habit of holding onto heat. For that reason, many of the best memory foam mattresses use graphite-infused foams to add temperature regulation that would otherwise be non-existent.

Latex foams are already breathable thanks to the natural ventilation properties of the material. However, graphite infusions can be used to enhance the inherent cooling.

Cooling mattresses with graphite

Graphite is used in many of our favorite cooling mattresses and mattress toppers from leading sleep brands. Here is a selection of beds and toppers with graphite:

Alternatives to graphite in cooling mattresses

There are many cooling materials and technologies in mattress manufacturers' tool belt, to help sleepers regulate their body temperature overnight. Here are five common cooling alternatives to graphite:

1. Copper foam

Similar to graphite, copper is a high-conductivity element that is infused in mattress foams to aid cooling and enhance sleep hygiene.

Thanks to the thermal conductivity of the element, copper can draw heat from the body and disperse it, so warmth is able to leave through the mattress surface.

Copper is also naturally antimicrobial, meaning it stops dust mites and allergens from harboring in your bed.

Mattresses known for their use of copper for include the Brooklyn Bedding CopperFlex mattress and our top rated cooling mattress; the Bear Elite Hybrid mattress.

2. Smart cooling technology

The best smart beds you can shop right now come complete with cutting edge technology targeting common sleep woes, one of which is temperature regulation.

A couple laying in Sleep Number ClimateCool smart bed — (Image credit: Sleep Number)

Temperature regulating smart beds are often fitted with water or fan based cooling systems, paired with temperature tracking sensors. When the sensors notice your body heat rising, they increase the cooling to ensure you stay at an optimal sleep temperature all night long, getting the best quality sleep possible.

3. GlacioTex

GlacioTex is a fabric woven of fibers with high thermal conductivity that work to transfer heat away from your body and the air.

GlacioTex fabric is often used in mattress covers so the bed remains cool to touch. We've found it to be an effective cooling fabric, albeit a littler slippery.

This material is found in many top-performing cooling mattresses and mattress protectors including the Brooklyn Bedding Aurora Luxe Hybrid Mattress and Nolah GlacioTex Cooling Mattress Protector.

4. Open cell structures and materials

Mattresses with open spring structures are naturally more cooling than all foam mattresses, as air can freely flow through the springs to improve heat dispersion and temperature regulation.

The Nolah Natural 11 Mattress in a well-lit bedroom — (Image credit: Future)

The best hybrid mattresses contain individually encased coils. These open coils have space for warm air from the body to pass through and be released the other side, helping heat to escape the mattress.

In some cases, hybrid mattresses will pair the breathable springs with heat conducting materials, such as graphite infused foams.

Other naturally breathable mattress materials include wool and cotton. These are used in the best organic mattresses and have a looser weave, allowing for better air circulation.

5. Celliant

Celliant is a thermo-reactive synthetic fiber that captures body heat and converts into infrared energy.

While most cooling materials trap and disperse heat into cold patches, Celliant does things a little differently. It holds this heat and releases it back to the body when you cool down. By doing so, it helps you regulate your body temperature.

Bear Elite Hybrid mattress — (Image credit: 3Z Brands for Tom's Guide)

The infrared energy also promotes blood circulation, aiding muscle recovery. Celliant is primarily used in the Bear Elite Hybrid, making it a popular mattress among athletes, as well as hot sleepers.

Does every cooling mattress need graphite?

Graphite sits among a catalog of mattress cooling methods, offering a scientifically-backed cooling solution. However, it is not the only means of temperature regulation in mattresses, so not all cooling mattresses need it.

The other cooling methods discussed above offer ample cooling on their own, or they can be used in conjunction with each other, or with graphite, for extra climate control.

Check out our guide on what to look for when buying in a cooling mattress for more information on how to buy mattress to handle your night sweats, hot flushes, or warm nights.

Eve is a PPA-accredited journalist with an MA in Magazine Journalism from Cardiff University. She is a Sleep Staff Writer at Tom’s Guide and has four years’ experience writing health features and news. She is particularly interested in the relationship between good sleep and overall health. At Tom’s Guide Eve is responsible for coverage and reviews of sleep tech and is our smart and cooling mattress specialist, focussing on brands such as Eight Sleep and Sleep Number. She also covers general mattress reviews, seeks out the best deals to produce tried-and-tested buyer's guides for sleep accessories and enjoys writing in-depth features about sleep health. She has been involved in rigorous testing procedures for mattress reviews in our Sleep Studio and has interviewed experts including sleep doctors and psychologists. When not covering sleep at Tom's Guide, Eve enjoys writing about health and fitness, food and culture.