As record-breaking heat waves become more common, companies are racing to develop new ways to protect people from dangerous temperatures. One of the latest innovations comes from Japan, where a refrigeration manufacturer has introduced what it calls a “human refrigerator”, a walk-in cooling booth designed to quickly lower body temperature and help prevent heat-related illnesses.

Known as the Do Hiemon Box, the cooling booth allows one person to step inside for a short session of chilled air. The company behind the product says users can begin feeling cooler within five minutes, making it a potential solution for outdoor workers and others exposed to prolonged heat.

TL;DR

• Japan’s SDRS has developed the Do Hiemon Box, a one-person cooling booth dubbed a “human refrigerator.”
• The booth is pre-cooled to 15°C (59°F) and blows 5°C (41°F) air onto the user’s head, neck, shoulders, and back.
• The company says five minutes inside provides noticeable cooling, while a 10-minute session helps lower body temperature.
• It is aimed primarily at construction sites, factories, outdoor events, and workplaces exposed to extreme heat.
• The unit costs 1.5 million yen (about $9,300 or ₹9 lakh) and is currently sold only to businesses and organisations.

What Is the Do Hiemon Box?

The Do Hiemon Box is a portable cooling booth created by Japanese refrigeration and vending machine manufacturer SDRS.

Unlike wearable cooling devices or portable fans, the booth is large enough for one person to sit inside while cold air circulates around the upper body. The concept draws inspiration from Japan’s refrigerated vending machines, which are commonly used to keep beverages chilled during the country’s hot summers.

The booth is designed as a rapid cooling station rather than a room where people spend extended periods.

How Does the Human Refrigerator Work?

The cooling process is straightforward but carefully controlled.

Pre-cooled interior

The booth maintains an interior temperature of 15°C (59°F) before anyone enters.

Targeted cold airflow

Once someone sits in the built-in chair, chilled air at 5°C (41°F) begins flowing toward areas where the body loses and gains heat quickly, including:

• Head
• Neck
• Shoulders
• Upper back

Instead of cooling the entire body evenly, the system focuses on these key areas to deliver rapid relief from heat.

Automatic shutoff

To prevent users from becoming too cold, the booth automatically powers down after 20 minutes.

Users can also choose from three different airflow and cooling settings, depending on their comfort level.

How quickly does it cool the body?

According to SDRS:

• Users begin feeling noticeably cooler within five minutes.
• Around 10 minutes inside the booth can significantly reduce body temperature.
• Lower body temperature may help relieve early symptoms associated with heat exhaustion.

While the booth is not a medical device or treatment for severe heatstroke, rapid cooling is widely recognized as one of the most effective first responses to overheating.

Who is the Do Hiemon Box designed for?

Rather than targeting consumers, SDRS developed the booth primarily for workplaces where employees spend long hours in high temperatures.

Potential users include:

• Construction workers
• Factory employees
• Road maintenance crews
• Warehouse workers
• Outdoor event staff
• Delivery personnel
• Agricultural workers

These professions often require prolonged exposure to direct sunlight or hot industrial environments, increasing the risk of heat exhaustion and heatstroke.

The portable design also means employers can move the unit between job sites without permanent installation.

Why is Japan investing in cooling technology?

Japan has experienced increasingly intense summers in recent years, with climate change contributing to more frequent and prolonged heat waves.

Tokyo and other cities have repeatedly issued heatstroke alerts as temperatures climb well above seasonal averages.

According to reports, 48 people were hospitalized with heatstroke in Tokyo on July 15 alone during one period of extreme heat.

An aging population, dense urban development, and the urban heat island effect have all increased concerns about protecting vulnerable people during summer months.

As a result, Japanese companies have introduced a range of cooling technologies, including wearable air conditioners, cooling fabrics, smart fans, and now enclosed cooling booths.

How is it different from a regular air conditioner?

SDRS says the Do Hiemon Box offers several advantages over conventional spot air conditioners.

Lower energy consumption

The company says the booth uses about half the electricity required by a comparable spot air conditioner.

Portable design

Unlike many cooling systems, the booth:

• Includes wheels for easy movement
• Requires no permanent installation
• Can be relocated wherever cooling is needed

Focused cooling

Instead of cooling an entire room, the system directs chilled air toward one person, making it more energy efficient in workplaces where employees take turns cooling down.

How much does the Do Hiemon Box cost?

The standard version is priced at:

• 1.5 million Japanese yen
• Approximately $9,300
• Roughly ₹9 lakh, excluding taxes

At present, the product is available only to businesses and organizations, not individual consumers.

Since its launch in April, SDRS says demand has been strong.

One public installation is located at Maebashi City Hall in Gunma Prefecture, where visitors can use the booth free of charge during periods of extreme heat.

Could human refrigerators become more common?

As temperatures continue to rise worldwide, cooling technology is evolving beyond traditional air conditioning.

Employers in industries such as construction, logistics, mining, and manufacturing are increasingly looking for practical ways to reduce heat-related illnesses while minimizing energy consumption.

Portable cooling booths like the Do Hiemon Box could become one option alongside shaded rest areas, hydration stations, wearable cooling devices, and climate-controlled shelters.

Whether the concept gains traction outside Japan will likely depend on factors such as cost, workplace regulations, and demand in regions experiencing more frequent extreme heat events.

The bigger picture

Extreme heat is becoming one of the world’s fastest-growing public health risks. According to health experts, prolonged exposure to high temperatures can lead to dehydration, heat exhaustion, and life-threatening heatstroke if not addressed quickly.

The Do Hiemon Box represents a novel approach to workplace safety—using targeted, rapid cooling instead of cooling entire buildings. While it won’t replace broader heat protection measures, it highlights how companies are adapting to a warming climate with specialized technologies designed to keep workers safe.