Protecting Lives from Extreme Heat: Home Heat Stroke Prevention Strategies

Introduction to Heat Stroke Prevention at Home

In recent years, extreme heat waves have become a common occurrence, endangering lives and health. The Japan Sashes Association (JSA), based in Minato, Tokyo, has established an Information Center for Comfortable Living, dedicated to providing unbiased and public service-oriented information on wellness living and measures against summer heat.

Rising Temperatures and Heat Alerts

According to forecasts, 2024's average global temperature is projected to reach an alarming 15.10°C, surpassing previous records since 1850. Japan is not exempt, with the frequency of heat stroke alerts steadily increasing. In 2024, the country recorded the highest number ever—1,722 heat stroke alerts—indicating a concerning trend of prolonged warm seasons. Moreover, alerts in September 2024 were approximately 3.6 times that of September 2023.

Heat Stroke Incidents Occurring at Home

Statistical data from the Fire and Disaster Management Agency highlights that nearly 40% of heat stroke incidents occur within homes. This is particularly troubling as homes should be safe havens. Disturbingly, the risk of developing heat-related illnesses inside residences is significant.

Insufficient Insulation in Existing Homes

Surprisingly, approximately 80% of homes in Japan do not meet current insulation standards. Houses lacking adequate thermal performance experience significant heat influx from the outdoors during summer. Data shows that windows allow 73% of this heat to enter, emphasizing the necessity of window renovations for effective summer heat management.

The Economic Benefits of Window Renovation

Upgrading to high-performance insulated windows (such as resin frames combined with Low-E triple-glass) can significantly reduce energy costs. Compared to conventional single-pane aluminum windows, these high-efficiency models offer performance differences of up to seven times in thermal transmittance (UW value). A cost analysis from the Advanced Window Renovation 2025 initiative estimates that renovating all windows in single-family homes in the Kanto to Kyushu regions to high-performance models could save homeowners approximately 20,000 yen annually on energy bills. Furthermore, if 70% of residences nationwide (noting that most have older aluminum and single-glass windows) switched to improved windows, total savings could amount to approximately 680 billion yen per year.

Utilizing Subsidies for Window Insulation Enhancements

There are two primary options for enhancing window insulation: either upgrading existing windows (through glass or frame replacements) or adding inner windows. Many people rely solely on air conditioning for comfort, not realizing that replacing conventional windows with insulated alternatives can reduce the air conditioner's workload, leading to energy savings and a healthier living environment. The Environment Ministry is currently running the Advanced Window Renovation 2025 initiative, which offers grants covering about half of the renovation costs for window upgrades, allowing homeowners to reduce their financial burden significantly.

Conclusion

As the Japan Sashes Association highlights through its initiatives, the challenges posed by extreme heat are serious and warrant immediate attention and action. Home renovations, especially concerning window insulation, are critical to ensuring safety and comfort during increasingly hot summers.

For further details, you can download the comprehensive report from the Japan Sashes Association's official website:
Download Report.pdf)

About the Japan Sashes Association
Founded in 1954, the Japan Sashes Association aims to advance the building materials industry related to sashes, doors, shutters, and exteriors through research, enlightenment, and technical standards. The organization promotes healthy environments and aims to elevate the quality of living for the citizens of Japan.

About the Comfortable Living Information Room
Established within the Japan Sashes Association in July 2025, this initiative is a collaborative effort among four sash manufacturers to share valuable information on wellness living and heat management for a comfortable residential environment.