[Battling the Heat] Experience -10°C! How Does the Heat-Shielding Hat "-TEN°" Make Scorching Weather Comfortable?

Japan's summer is only getting harsher, with record-breaking heat waves continuing every year.

Still, while we all want to protect ourselves from the heat, carrying a parasol can feel like a hassle. For those facing this dilemma, there's a must-try item: the -TEN° hat, which claims to lower your perceived temperature by 10°C just by wearing it.

How did they make this hat so incredibly comfortable and easy to wear while delivering such an impressive “minus 10°C” cooling sensation? We spoke with Midori Ito from Cross Plus Inc. to uncover the secret.

The Special Aluminum Fabric Enabling a Minus 10°C Sensation

At first glance, it looks like a hat you could wear every day. But as soon as you slip your hand inside, you'll feel an impressively cool sensation.

Originally launched for the Spring/Summer 2024 season as part of the "hat series specializing in extreme heat measures", the -TEN° series quickly gained popularity. Now, this season, it has been upgraded and reborn as its own standalone brand, "-TEN°."

The heart of its cooling effect is a special aluminum fabric sandwiched between the outer and inner layers of the hat’s crown.

"Conventional aluminum fabrics used to be stiff and had a rough texture. While commonly used in agricultural tarps, hats, or car sunshades, they were heavy and uncomfortable when used in everyday hats, making them stuffy inside as well.

"With recent intensifying heat waves, we searched for a heat-shielding material suitable for the crown of daily hats and finally found this fabric."

The aluminum fabric Ito showed us resembles organza, with a translucent look and a subtle silvery sheen.

This light, flexible fabric directly reflects heat-causing infrared rays, blocking the transfer of heat to the head.

"It’s a high-performance fabric combining softness, thinness, and functionality. However, choosing the right outer fabric to maximize its performance was quite a challenge."

To achieve full heat-shielding, the aluminum layer needs to get some direct light. Dense weaves like twill or denim block the light before it can reach the aluminum, reducing its effectiveness.

But if you use a very loose fabric, the aluminum lining becomes visible, making it unsuited as a fashionable daily accessory.

"The challenge was balancing enough light exposure to the aluminum to keep the -10°C data, without making the inside visible, and still matching everyday fashion. After much trial and error with several materials, for this season we chose cotton-linen and polyester fabrics with just the right weave."

Furthermore, the lining features a contact-cooling fabric for even more comfort.

With three layers—outer, aluminum, and contact-cooling—the hat achieves a 10°C temperature difference.

Data-backed Reliability & Comfort Hidden in Every Detail

The cooling effect of -TEN° is scientifically backed by tests from third-party labs.

Both unprocessed hat materials and the 3-layer structure (aluminum plus contact-cooling layers) used in -TEN° were exposed to artificial sunlight for 30 minutes. The resulting temperature rise was measured, and results showed a temperature difference of over 10°C, with a heat-shielding value of S65+ (cuts 65% of heat).

This isn't just a vague, sensation-based claim; it’s reliable performance, backed by hard data, that supports the trust in this product.

In addition to its heat-shielding power, every hat is equipped with ventilation holes to enhance breathability—a key detail.

Thanks to these features, you’ll notice an even greater cooling sensation than the data suggests when you actually wear the hat.

The brand's commitment extends not only to functionality but also to a strong sense of fashion.

They have eliminated the ruggedness or dowdiness often associated with function-first hats, focusing instead on a simple design that seamlessly blends into everyday outfits.

"The lineup is divided into a hat category, perfect for wearing around town, and a cap category, ideal for outdoor active scenes, offering products that can match any fashion or situation."

The lineup features classic styles such as adventure hats, bucket hats, and caps, with a basic color palette—black, off-white, navy, and more—designed to coordinate effortlessly with any wardrobe.

Furthermore, there is a keen attention to the smallest details.

For example, the ribbon embellishment on the hat-type "-TEN° Stitch Sailor" is not just a decorative touch. By untying the ribbon and threading it through the slit on the brim, it can be used as a chin strap, ensuring a secure fit on windy days or while riding a bicycle.

The forehead area is lined with sweat-absorbent tape, and the high-drying material minimizes discomfort from summer sweat while providing an adjustable fit.

Such subtle yet thoughtful details show consideration for the wearer.

Expansion to Men's & Kids' Items

"-TEN°" previously offered just one size, but with the brand's latest launch, both men's and kids' sizes have now joined the collection. Now, the whole family can enjoy the cool comfort of "-TEN°."

In the kids' line, special care has been taken in design to accommodate children's behavior and physical characteristics.

"For example, for kids who spend lots of time playing outdoors, we've added a neck shade at the back. Children also tend to sweat more on their heads, so we've increased the mesh areas to maximize breathability."

This June saw a record number of days with temperatures exceeding 30°C—marking the hottest on record. Many people likely feel that the heat is arriving earlier every year.

"In reality, sales of sunblock items this year were already strong from early spring, March and April, with some items nearing sell-outs due to high demand.

"This increasing demand for heat protection is evident every year, so going forward with -TEN°, we're hoping to introduce not only hats but also fashionable sun-shielding accessories like neckwear and outer layers."

Summer is just getting started, and the risk of heatstroke will continue to climb. We hope that adopting parts of "-TEN°," which can make you feel up to 10°C cooler, helps everyone enjoy a more comfortable summer.