Japan enforces heat safety rules across workplaces

Japan is turning up the heat on workplace safety, introducing stricter rules that compel employers to shield workers from extreme temperatures or face hefty fines.

As of 1 June, businesses must take concrete steps to prevent heat-related illness or risk penalties of up to ¥500,000 (US$3,475). The move is a rare example of a nationwide policy on occupational heat safety, positioning Japan as a pioneer in addressing climate-linked risks to labour.

There is urgency behind the legislation. In 2023, Japan endured its hottest July on record, with temperatures pushing many workers past the point of endurance. The health ministry reported around 1,200 heat-related injuries and 30 workplace deaths that year alone, largely among those in construction and manufacturing.

The new law is a direct response to these alarming figures, as well as to mounting global concern about the economic and human toll of rising temperatures.

Heatstroke is more than just discomfort. It’s a medical emergency that can quickly spiral into permanent organ damage or even death.

Globally, the World Health Organization reported almost half a million people died each year from heat-related causes between 2000 and 2019. In workplaces, especially outdoor or high-exertion environments, the danger is amplified.

The revised Japanese regulations mandate swift identification and treatment of heatstroke symptoms. Employers must provide emergency transportation, promote the use of wearable tech to monitor body temperature, and implement a buddy system to ensure no worker is left to face the heat alone.

A cornerstone of the new approach is the monitoring of the Wet Bulb Globe Temperature (WBGT) index, a measurement that accounts not only for temperature, but also humidity and solar radiation. When the index exceeds 28°C or when ambient temperatures climb above 31°C for prolonged periods, employers must activate safety protocols.

This isn’t just about keeping workers comfortable. Research shows that productivity plummets as the mercury rises.

According to a 2019 International Labor Organization study, workers performing moderate-intensity tasks can lose up to 50% of their work capacity at temperatures between 33°C and 34°C.

Without a reduction in greenhouse gas emissions, the same study projects a global economic hit of US$2.4 trillion by 2030 due to heat stress.

Some of Japan’s largest employers are already getting ahead of the curve. Shimizu Corp, a major construction firm with more than 20,000 employees, is integrating wearable devices and heat index-based break schedules into its standard safety procedures.

Yamato Transport Co, a household name in parcel delivery, is also taking proactive steps – though not directly in response to the new regulations. The company plans to distribute 75,000 fan-equipped vests to staff, including those on bicycles and foot, and install 3,000 WBGT measurement devices across its sites. These initiatives speak to a broader shift in corporate thinking: heat risk is no longer a seasonal nuisance but a year-round operational challenge.

While Japan’s move is groundbreaking on a national scale, it’s part of a broader international reckoning with heat-related workplace risks. In the US, California and Washington state have developed their own heat protection frameworks.

The federal Occupational Safety and Health Administration is also in the process of establishing national standards, noting that the country saw an average of 40 heat-related workplace deaths per year between 2011 and 2020.

With global temperatures crossing the 1.5°C threshold above pre-industrial levels for the first time in 2024 and more records expected in the years ahead, Japan’s bold stance may serve as a blueprint for others.

As climate change turns up the dial on workplace conditions, businesses worldwide will be under pressure to keep their cool – and protect their people.