If you’ve ever woken up tangled in damp sheets, searching for the cool side of the pillow, you know how much temperature can shape your sleep. Some people sleep warm by nature; others are battling summer heat, hormonal changes, or simply bedding that traps too much warmth.
The truth is, sleeping cool is a science — and your sheets play a bigger role than you think.
In recent years, eucalyptus lyocell (also known as TENCEL™) has gained a reputation as the go-to fabric for hot sleepers. Silky to the touch yet refreshingly breathable, it’s become the centerpiece of modern “cooling bedding.” But what makes it work so well?
Let’s unpack the science.
The Hidden Problem with Most Sheets
Most traditional sheets — especially those made from dense cotton or synthetic blends — act like insulators. They trap heat close to your body, allowing moisture to build up throughout the night.
When your core temperature rises, your body begins to sweat as a cooling mechanism. But if your sheets can’t wick away moisture, that sweat lingers. You overheat, your skin feels sticky, and your sleep cycle is disrupted.
That’s why “cooling sheets” have become one of the most searched-for bedding categories online — because millions of people are looking for a fabric that breathes.
Enter Eucalyptus Lyocell
Eucalyptus lyocell is a cellulose-based fiber derived from sustainably grown eucalyptus trees. It’s created through a closed-loop process that recycles 99% of the water and solvents used — a win for both comfort and the planet.
But what makes it uniquely cool lies in its microscopic structure. Under a microscope, lyocell fibers appear perfectly smooth and round, unlike cotton’s uneven, twisted surface. This difference affects how heat and moisture move across the fabric.
According to Eucalypso Home, lyocell outperforms cotton in thermal regulation, maintaining a more stable body temperature during sleep. The smooth surface also helps reduce friction against the skin — ideal for anyone who sweats or experiences irritation at night.
In other words: it doesn’t just feel cooler. It is cooler.
The Science of Staying Dry
Cooling is only part of the equation; staying dry is the rest.
TENCEL™ Lyocell fibers are naturally moisture-wicking, meaning they draw sweat and humidity away from your body and release it into the air faster than cotton. The fabric can absorb up to 50% more moisture than cotton but still feel dry to the touch.
This is because eucalyptus fibers are hydrophilic — they attract and release water vapor efficiently, keeping your skin’s microclimate balanced. The result is a consistently cool, dry sleep surface that prevents that clammy “stuck to your sheets” feeling many hot sleepers know all too well.
Why the Fabric Itself Feels Cool
The cooling sensation of eucalyptus sheets isn’t just psychological. The fibers have a naturally low thermal conductivity, meaning they don’t retain body heat.
Where cotton fibers absorb and hold warmth, eucalyptus fibers allow air to move freely through their structure. Combine that with a smooth, dense weave (often sateen or twill), and you get that signature “cool-to-the-touch” feeling that lasts even after hours of sleep.
It’s not uncommon for first-time users to describe it as “sleeping on silk, but cooler.”
What About Other Cooling Technologies?
Eucalyptus lyocell isn’t the only option for hot sleepers, but it’s one of the most naturally effective. Other cooling bedding innovations include:
- Gel-infused mattress toppers, which help dissipate body heat from below.
- Breathable cotton percale sheets, known for their crisp, airy weave.
- Performance fabrics with synthetic cooling finishes (though these can lose effectiveness over time and feel less natural).
What sets eucalyptus apart is that it doesn’t rely on coatings, treatments, or additives — the cooling power is inherent to the fiber itself.
Comfort Without Compromise
Beyond temperature regulation, eucalyptus bedding brings other benefits hot sleepers often overlook. It’s naturally antibacterial, hypoallergenic, and resistant to dust mites, which means a cleaner, fresher sleep environment.
Because the fiber surface is smooth, it also reduces friction on the skin — a welcome change for anyone with sensitivities, eczema, or acne-prone skin.
And unlike synthetic “cooling” sheets, which can feel slick or plasticky, eucalyptus sheets maintain a soft, breathable luxury that feels effortlessly natural.
Cool by Nature, Not by Chemicals
If you were to rank cooling fabrics on both performance and sustainability, eucalyptus lyocell would sit firmly at the top. It manages to balance comfort, ethics, and science — proving that luxury and responsibility can coexist.
It cools not because it’s coated or engineered, but because nature designed it that way.
So if your nights are too warm or you find yourself kicking off blankets by 2 a.m., it might be time to rethink your bedding.
Experience Naturally Cool Sleep
At Loomii, we use 100% Eucalyptus Lyocell — a premium, closed-loop fabric that keeps you cool, dry, and comfortable all night long.
No chemicals. No gimmicks. Just clean, breathable sleep powered by nature.