As record-breaking heatwaves become more frequent around the world, keeping outdoor workers safe has become an increasingly urgent challenge. Japan may have come up with an unusual solution. A Japanese company has developed what many are calling a “human refrigerator”, a walk-in cooling booth designed to lower body temperature within minutes. Instead of cooling an entire room, the compact cabin focuses chilled air on key parts of the body to provide rapid relief from heat. The innovation is aimed at construction workers, factory employees and others who spend long hours in extreme temperatures, where heat stress and heatstroke remain serious occupational risks.
What is Japan’s ‘human refrigerator’?
The device, officially known as the Do Reimon Box, has been developed by Japanese industrial supplier TRUSCO Nakayama Corporation. It is a stainless steel, single-person cooling booth where users step inside, sit on a chair and close the door behind them for a short cooling session.The system has been designed as a portable cooling station that can be installed at construction sites, factories, warehouses and outdoor workplaces without requiring major infrastructure changes.
How does it cool the body in just minutes?
Inside the booth, the ambient temperature is maintained at approximately 15°C, while powerful jets of air cooled to around 5°C are directed towards the neck, head and back. These areas play an important role in regulating body temperature, allowing users to feel cooler much faster than standing in ordinary air conditioning.According to TRUSCO, spending five to ten minutes inside the booth is generally enough to provide noticeable relief from heat. The cooling session is automatically limited to 20 minutes to prevent overcooling.
Built to fight rising heatstroke cases
Japan has experienced increasingly intense summers over the past few years, with soaring temperatures leading to thousands of heatstroke-related illnesses every year. Outdoor workers are among the most vulnerable, particularly those in construction, manufacturing, logistics and road maintenance.The Do Reimon Box has been created specifically to help these workers cool down quickly during scheduled breaks before returning to work. It is intended to support workplace heat safety rather than replace hydration, rest or medical treatment.
Inspired by frozen food technology
Interestingly, the cooling booth draws inspiration from the refrigeration systems used in frozen food vending machines. Engineers adapted the same cooling technology into a human-sized cabin capable of delivering intense, localised cooling while remaining safe and comfortable for short-term use.The booth operates on a standard 100-volt power supply, can be moved on built-in casters and requires no permanent installation, making it suitable for temporary work locations and industrial sites.
Could this become the future of workplace cooling?
With climate change driving longer and hotter summers across many countries, technologies designed to protect workers from heat stress are attracting increasing attention. Personal cooling booths like the Do Reimon Box could become a practical addition to workplaces where traditional air conditioning is either impractical or ineffective.Although it is not a medical device and cannot treat heatstroke on its own, the Do Reimon Box represents an innovative approach to occupational heat management. As temperatures continue to climb globally, Japan’s unusual “human refrigerator” may offer a glimpse into how future workplaces keep employees safer during extreme heat.
