A Fresh Idea: "Chill Before You Wear!" Footmark's 'Hiyashitoku' Takes on Sweltering Heat

Footmark Co., Ltd. has unveiled its 'Hiyashitoku' series, a line of heat-busting apparel featuring PCM and a unique concept: "chill before you wear."

With scorching heatwaves becoming a major societal concern, how will this groundbreaking design—pre-chilling your clothes in the fridge—redefine comfort and peace of mind?

In this article, we sit down with Tomoya Kobayashi, the head of the company's Lifestyle Division and the driving force behind the product's development. He shares insights into the journey of adapting space-age technology for apparel and sheds light on the future of clothing in a world learning to live with intense heat.

Inspired by Bedding Pads: The Focus on 'Lasting Coolness'

The Japan Meteorological Agency reported that the summer of 2025 saw Japan’s highest average temperatures on record, with 9,385 locations officially logging "extremely hot days." As this relentless heat became a pressing social issue, tackling heatstroke became a top priority for Footmark, a company whose sales are dominated by children's products like swimwear. Tomoya Kobayashi, from the company's Lifestyle Division, was on a mission to develop a groundbreaking solution to beat the heat.

“When neck coolers started to become popular, I first became aware of a material called PCM (Phase Change Material). Later, when I saw it being used in bedding pads, I thought, 'Couldn't we apply this same process to the textiles we handle?'”

Traditional cooling apparel often relies on "contact cooling," which feels cold instantly, or "evaporative cooling," which uses moisture like sweat. But in today's extreme heat, those methods have their limits. Kobayashi sensed that PCM could offer a new solution: a longer-lasting cool that isn't dependent on factors like sweating or the weather.

Kobayashi's insight sparked Footmark's innovative project. PCM, originally developed by NASA to regulate temperatures in spacesuits, works by absorbing surrounding heat to maintain a steady temperature. He was confident that by embedding this technology into fabric, they could create apparel with a sustained cooling effect unlike anything else on the market.

The Quest for Technology to Create the Ideal Cooling Wear

While the idea of embedding PCM into clothing was groundbreaking, the journey to make it a reality was anything but smooth. Unlike the rigid resin rings used in neck coolers, anchoring PCM to the soft, flexible fibers of apparel without sacrificing comfort demanded incredibly sophisticated technology.

There was no room for compromise when it came to selecting materials. Since the clothing comes into direct contact with skin, safety was paramount. The team ultimately landed on a plant-derived PCM, a material so safe it's even used in the medical industry.

This PCM is microencapsulated in a polyurethane resin free of harmful substances like formaldehyde. Kobayashi describes the final texture:

“The capsules are incredibly small—about 20 microns. I was initially worried the fabric would feel stiff, but the final product turned out to have a surprisingly natural and comfortable feel.”

By using microscopic microcapsules, they succeeded in preventing the fabric from feeling stiff. Furthermore, by partnering with a European factory that possessed the technology to encapsulate a high ratio of 40-50% PCM within the capsules, the foundation for the cooling effect was established. However, the real challenge of turning this material into a finished "fabric" was just beginning.

The Search for a Partner Across the Sea and the Birth of "Téxion"

Although they had secured high-quality PCM material and micro-encapsulation technology, Footmark did not have its own factory for dyeing and processing fabrics. Therefore, they needed to find a partner to handle the process of bonding the material to the fibers.

Their search led them to a partner factory in China. However, even there, processing PCM into textiles was completely uncharted territory. The development team tested seven or eight different types of fabric, but they couldn't seem to get the results they were hoping for. In fact, even the fabric they eventually chose showed no significant temperature difference on its surface during the initial tests.

"When we saw no temperature advantage at all, we realized the PCM wasn't properly adhering to the fibers. We repeatedly tested different solvent mixing ratios and other variables to figure out how we could get more microcapsules to bond."

After countless rounds of trial and error, they finally succeeded in getting the PCM to firmly bond with the fibers. The result was "Téxion," a new material with a surface temperature up to 4°C cooler than unprocessed fabric. It also proved to be incredibly durable, retaining about 80% of its cooling power even after 20 washes. They had cleared a major hurdle on the path to commercialization. The team then moved on to the next crucial step: designing the experience of "delivering" this innovation to consumers.

Designing the "Chill-to-Wear" Experience for Everyday Life

Now armed with a powerful new material, the development team wasn't content to just let its functionality speak for itself. They set out to design an "experience" that would truly surprise consumers and let them feel the difference. Téxion has the unique ability to absorb heat and maintain a steady 28°C for a period of time. But to ensure users could fully appreciate this effect under the blazing summer sun, they needed one more trick up their sleeve.

"The temperature inside a closet isn't always below 28 degrees, so we need to make sure the PCM solidifies before you wear it. We figured, if we're going to do that, why not offer an unparalleled 'Whoa, that's cold!' experience by having people wear an ice-cold T-shirt?"

And so, the unique "chill in the fridge before you wear" concept was born. Just 15 minutes in the refrigerator cools the fabric down to about 5°C, completely solidifying the PCM. This achieved a two-stage experience: an intense, chilly sensation right when you put it on, followed by the pleasant, steady temperature maintenance that Téxion provides.

On the other hand, many consumers are understandably hesitant about putting their clothes in the refrigerator. To overcome this hurdle, the company got creative with its packaging. For T-shirts, the case is the same size as a 500ml water bottle. For items using less fabric, like arm covers and neck stoles, a dedicated transparent case half that height is available. This prevents any refrigerator odors from clinging to the clothes. It's a thoughtful touch designed to help this new habit fit seamlessly into daily routines.

Temperature-Regulating Tech for Every Lifestyle

The resulting "Hiyashi-Toku" series isn't just for outdoor adventures and leisure; it's designed for a wide array of scenarios. Take, for instance, professionals who constantly move between air-conditioned interiors and the sweltering outdoors.

Home-visit caregivers, for example, are constantly on the move, facing harsh temperature swings. This apparel is a game-changer: the PCM inside re-solidifies in cool indoor spaces, ready to deliver another blast of coolness when the wearer steps back out. It's a powerful tool for support. What's more, Kobayashi envisions the applications of this temperature-regulating technology extending far beyond the summer months.

"By leveraging the properties of PCM, we're also conceptualizing apparel for fall and winter that provides warmth, set to 31°C or 32°C. We're also exploring its use in the caregiving sector, such as reducing discomfort on wheelchair seats."

The company is also setting its sights on incorporating the technology into its core business: school gym uniforms. They are pushing forward with a clear objective: to protect children from heatstroke by maintaining 28°C for approximately 40 minutes during PE classes. This demonstrates their commitment to tackling social issues head-on with technology.

Footmark's "Hiyashi-Toku" series is one answer to the challenge of oppressive heatwaves. In an age of unprecedented climate change, the summer activities we've always taken for granted are facing new limits.

But the company is harnessing the power of technology to tear down these barriers, aiming for a society where everyone can live safely and comfortably. The mindset shifts from "I can't because it's too hot" to "I can enjoy this because I have this." This temperature-regulating technology offers a proactive choice, poised to make our lifestyles richer and more liberated.