Tokyo Fire Department promotes palm cooling to prevent heatstroke

The Tokyo Fire Department is promoting a cooling technique targeting the palms of the hands to help prevent heatstroke during extreme heat ^[1].

This method provides a rapid way to lower core body temperature, which is critical as heat-related emergencies continue to strain emergency services in Japan. In 2023, the number of people transported by emergency services for heatstroke in Tokyo exceeded 9,000 ^[2].

According to Wataru Sasaki of the Fire and Disaster Management Technology Research and Development Center, the effectiveness of the method relies on specialized anatomy. "In the palms of the hands, there are special blood vessels called AVA blood vessels," Sasaki said ^[1]. He said that by cooling the palms, the chilled blood circulates throughout the entire body, effectively reducing overall temperature ^[1].

During a demonstration at the Tokyo Fire Department Fire Academy in Shibuya Ward, officials showed how cooling the hands and arms for approximately five minutes can impact the body ^[1]. Kana Fukuyama, a weather forecaster involved in the demonstration, observed the results via thermal imaging.

"After cooling the hands and arms for about five minutes, the red areas that had heat in the thermal camera images became fainter, and it felt as though the heat in the body had subsided," Fukuyama said ^[1].

The urgency of such preventative measures is underscored by recent data. In 2026, approximately 1,000 people in Tokyo have already been transported for heatstroke ^[2]. The department said that targeted cooling can mitigate the risk of severe heat-related illness by leveraging the body's own circulatory system to distribute coolness from the extremities to the core.