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Bedding Uses Volcanic Mineral 37.5 Technology to Balance Sleep Temperature

Jennifer Nelson & Sarah Panus

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What seems like magic, is actually science. Are you one of the millions of sleepers who have trouble regulating your body temperature during sleep? How volcanic minerals may help.


There's a scientific explanation for how 37.5® Technology embedded in the yarn of True Temp™ bedding works. This natural volcanic mineral technology is responsibly-sourced, so you can rest comfortably.


If you're one of the millions of sleepers who have trouble regulating your body temperature, Sleep Number may be able to help you with their True Temp™ bedding.


The temperature balancing bedding features 37.5® Technology, which continuously adapts to help keep your bed's climate at your optimal temperature and relative humidity level.


Sleep Number spoke with Serine Steinnes, EVP of Global Home, to get the scientific scoop on 37.5® Technology and just how it works to keep you comfortable while sleeping.


What Is 37.5 Technology?

First, 37.5® Technology gets its name from the ideal body temperature — 37.5° C. This temperature is good for peak athletic performance, and also relative humidity for sleeping comfort. It was created by a PhD photo-physical chemist and inventor.


While doing postdoctoral work in Japan, not even thinking about anything related to temperature regulation or humidity management, he visited a traditional volcanic mineral bath, known for their restorative and purifying properties.


While there, immersed up to his head so only his face was above the volcanic sand bath, he felt warm but not hot, wasn’t soaked in sweat, and thought it was interesting and quite comfortable though he was packed into the sand.


“It sparked his interest," says Steinnes. "Like, what could I do with these volcanic minerals to find a way to manage core body temperature through moisture management?'"


So, when he got back to the U.S., he figured out how to permanently embed volcanic minerals into fabric. And 37.5® Technology began as an apparel technology—for cooler, more comfortable, keep-body-core-temperature-down, sweat less clothing.


Once the technology was in apparel, it moved to the home space, where it makes even more sense in bedding that is designed to keep you comfortable and dry throughout the night.


True Temp Bedding: Like Magic

So how does smart True Temp™ bedding technology work? While it seems like magic, it's really just science.


The technology uses active particles from natural volcanic minerals that have billions of micropores. They have the ability to capture human infrared or IR energy or light, which is infrared radiation that humans give off, kind of like an 80-watt light bulb we constantly emit.


And the volcanic minerals also capture moisture at the vapor stage before liquid forms on the skin, which means they're hydrophilic. 37.5® Technology uses your body’s IR energy to speed the evaporation of moisture, helping your body cool itself efficiently and quickly. 


“So, we have both a heating and cooling mechanism, depending on what your body needs, essentially in real time," Steinnes says.


Most impressive about the technology, it's triggered by humidity, or moisture. So, your body “tells" the technology, “I'm hot and sweaty," or “I'm cool and dry." And it's the sleeper who triggers the technology to activate whether to help you stay warm or help you cool down, using the body's energy.


Now you see why we said it's kind of like magic??? Sleep science is so amazing.


Sleeping Hot and Cold

Most people may say they want to sleep “cool" but what they really mean is they want to sleep balanced.


When you sleep, your body goes in and out of different sleep cycles. As you go into a REM cycle, the deep dream state of sleep, you lose the ability to properly cool your body, Steinnes explains.


The body has a shutdown mechanism, so you don't get up out of bed and start acting out your dreams. And part of that process means that you're not able to cool down quickly.


That's why when you come out of those REM cycles, you tend to be hot. And you go through three, sometimes four of those a night — cycling in and out of feeling both hot and cold depending on where you are in the sleep cycle.


During sleep, most people likely pull the covers up when cold, kick their legs out from under the covers when hot, switch positions or turn the pillow over looking for a cool spot — constantly cycling in and out of REM and feeling both hot and cold. You may wake up and remember it or not.

What 37.5® Technology does is help regulate those disturbances. Infrared heat is produced and used to power the particles. When you get too warm and start to perspire, it grabs moisture and pulls it away before liquid sweat forms on the skin. 


“You don't need to have liquid sweat form to cool off. It gets the moisture away before you're actually wet," Steinnes says.




Is True Temp Bedding Right for You?

Bedding with 37.5® Technology is an investment that solves multiple sleeping problems common to many.


How would it feel to be in the same bed with your partner — one of you is a hot sleeper and one is a cold sleeper — and you're both comfortable with the same 37.5® bedding at the same time.


“It can help one sleeper stay warm and help cool the sleeper next to them simultaneously,” Steinnes says.


Can You Wash the Technology Away?

No. It’s permanent and performs for the life of the product.


As for the application of the technology, the natural volcanic minerals are embedded into the fabric, into the very yarn, or in the case of filled bedding like comforters, they're also embedded in the fibers inside it.


It's not a topical treatment or spray-on that can ever be worn off; it's permanent for the life of the product.


Plus, Steinnes says, testing shows the effects are cumulative. You get results with the sheets, of course, and if you use a 37.5® blanket like a True Temp™ blanket on top of that, along with a True Temp™ Layer, you get even more temperature regulation. It works alone or as a system.



Even better, the volcanic minerals for 37.5® Technology are responsibly-sourced, and fibers with 37.5® Technology are GRS certified, and Hohenstein Institute safe for allergens.


Plus, when your 37.5® bedding eventually gets super old and worn out, you'll be happy to know that 37.5 yarns have an additive which enhances biodegradation* in landfills, which allows the material to biodegrade over decades instead of centuries when it's finally ready for the landfill.


If you think your sleep quality is affected by being too hot or too cold, or if you're looking for a cooler pillow or warmer feet, you may want to give cooling Sleep Number True Temp™ sheets a whirl. Sheets that keep you cool, comfortable and balanced could be sleep-changing.



[Shop True Temp™ Sheets Now]

[Shop True Temp™ Layer Now]



Like diet and exercise, quality sleep is essential for optimal well-being and performance. Because everyone's sleep needs are different, Sleep Number® smart beds, with SleepIQ® technology inside, sense your movements and automatically adjust firmness, comfort and support to keep you both sleeping comfortably. Find your Sleep Number® setting for your best possible night's sleep.



Jennifer Nelson is a Florida-based health writer who writes about all things sleep hygiene. She writes for The National Sleep Foundation, Phillips, Tom's Guide, Southern Living, Health, AARP, and others.


Sarah Panus is the Editor-in-Chief of the Sleep Number blog, owner of Kindred Speak, and host of the Marketing With Empathy podcast.

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