Heatstroke in Japan: current status, future risks, and prevention measures under a changing climate

Temperatures in Japan have been rising due to climate change, with 2025 recording the highest average summer temperature on record. Consequently, the health impacts of rising temperatures have become increasingly severe, with heatstroke representing a major concern. Recently, over 90,000 people have required ambulance transport for heatstroke, and more than 1500 deaths have occurred annually. Among all age groups, older adults are the most vulnerable to heat exposure. As Japan becomes a super-aged society and climate change intensifies, the risk of heatstroke is projected to increase further. To mitigate this risk, the Japanese and local governments have implemented a variety of heatstroke prevention measures (HPMs). This paper introduces these measures and highlights lessons learned from Japan's experience, which may inform the development and implementation of HPMs in other regions and countries. In this study, HPMs were identified and organized using materials from the Japanese and local governments, and a narrative review of the HPMs was conducted.