KING SALMON PROJECT

During the World Athletics Championships Tokyo 2025, SPACECOOL INC. completed a deployment and evaluation project for heat‑mitigation products designed to improve outdoor event environments and reduce heat‑stress risk.

As part of the project, SPACECOOL provided tent canopies made with “SPACECOOL,” a radiative‑cooling material that reflects solar radiation while passively emitting heat as infrared energy into outer space. These tents were installed around the exterior of the Japan National Stadium and at Meiji Park and Yoyogi Park for use by athletes, staff, and spectators.

The study assessed three outdoor conditions—under a SPACECOOL tent, under a conventional tent, and in open areas—by comparing environmental indicators and human physiological responses and collecting qualitative feedback from users to verify effectiveness for outdoor events. The verification was conducted in collaboration with Professor Shinji Yoshida’s research group at Nara Women’s University.

Compared with conventional tents, the SPACECOOL tents reduced air temperature by 1.8°C, globe temperature (black-globe temperature, reflecting radiative and convective heat load) by 5.4°C, and mean radiant temperature (MRT, a proxy for perceived radiant heat) by 9.4°C. In addition, the wet‑bulb globe temperature (WBGT) decreased by one risk category, and core body temperature—an indicator of heat‑stress risk—showed a downward trend. Qualitative evaluations also rated the perceived coolness of the SPACECOOL tents highly, confirming their effectiveness as a heat‑mitigation measure in hot outdoor environments.

Looking ahead, SPACECOOL INC. will promote broader adoption of SPACECOOL materials across outdoor sports events and public gatherings, as well as in public spaces and disaster‑response hubs, advancing a scalable, sustainable deployment model for heat‑resilient infrastructure.