Written by: Jin Fujisaki / Published: 2026-01-30
Summer in Japan has reached disaster-level intensity. Blasting yourself with hot air from a handheld fan is pointless. For business professionals who have to make the rounds in a suit, sweating has been an unavoidable bug.
Sony's "REON POCKET 5" isn't a device that lowers the outdoor temperature—it's a device that pinpoints and rewrites only "the temperature at the back of your neck." And it doesn't just cool. It can warm you up in winter, too. This is a wearable air conditioner—a thermal interface that extends your body's capabilities.
| A "Heatsink" You Wear on Your Back
image SONY
The REON POCKET 5 is, at its core, a smartphone-sized white box. You attach it to the base of your neck using a dedicated neckband.
The stainless-steel surface that touches your skin cools down or warms up. The mechanism behind this is the "Peltier element"—the same technology used to cool PC CPUs. When electricity flows through it, one side absorbs heat (cooling) while the other side generates heat. This physical phenomenon is harnessed to directly cool the neck, where the carotid artery runs.
In the latest "5," heat absorption performance has been improved by up to approximately 1.5 times. Fan noise has also been reduced to about one-fifth, pushing "stealth" capability for business settings to the limit.
| Why This Shape?
image SONY
The obsession with "cooling" is evident in the device's internal engineering.
- Heat Exhaust Control: No matter how much you cool the neck, it's meaningless if exhaust heat gets trapped. The REON POCKET 5 features a redesigned intake and exhaust layout, achieving an airflow that efficiently releases heat even when you're wearing a high-collared shirt.
- Five Sensors: Equipped with a total of five sensors measuring temperature, humidity, acceleration, and more. This enables autonomous temperature management, such as "stronger cooling while walking" and "weaker cooling when seated."
- TAG Integration: With the separately sold "REON POCKET TAG," you can sense not only the temperature inside your clothing but also the surrounding environment. The moment you step into an air-conditioned train, cooling automatically switches off. The user no longer has to do anything.
| Your Personal "Microclimate"
image SONY
Stepping out into the city wearing the REON POCKET 5 wraps you in a strange sense of omnipotence.
While everyone around you walks by drenched in sweat, you alone keep your cool. It's a sharp, crisp coldness—as if an ice pack were pressed against your back. Yet the moment you board a train, that chill quietly fades away.
Before you even feel "hot," the device gets ahead of the situation and handles it. It's like having your own personal climate-control attendant trailing behind you at all times. You can manually adjust the temperature level via the smartphone app, but if you leave it to the excellent "SMART COOL MODE," your battery will last longer, too.
| Who Is It For?
image SONY
This product is essential gear for anyone who wants to perform at their best regardless of their environment.
- Suit-Wearing Warriors: Those who want to power through Japan's summer—where even Cool Biz has its limits—without breaking a sweat.
- Gadget Geeks: Those who want to manage even their own body temperature numerically through an app.
- People Sensitive to Temperature Swings: Those who easily feel under the weather from the gap between the summer heat outdoors and the over-air-conditioned office (since it handles both cooling and heating, you can use it year-round).
| Conclusion | Updating Your Body's OS
image SONY
So, what do you think?
The REON POCKET 5 is part of your clothing, and part of your body.
The era of "endure it because it's hot" is over. Comfort is something you acquire through technology. Just by hanging this small device around your neck, your summer transforms into a "conquerable quest."
