Health experts in Japan are promoting "pre-cooling" as a strategy to prevent heatstroke during periods of extreme heat [1].
This method is significant because it targets the core body temperature before a person enters a high-temperature environment, potentially reducing the risk of heat-related illness before the body begins to overheat.
Pre-cooling involves a dual approach of external and internal cooling. Externally, this can include soaking hands and feet in ice water. Internally, the method involves consuming slush or crushed ice [1, 2].
Koji Fujita, head of General Internal Medicine and Infectious Diseases at Tsuyama Central Hospital, said the goal is to cool the body before it becomes hot. Fujita said that cooling from both the outside and the inside is essential for the process [1].
According to medical guidance, the process should be performed 20 to 30 minutes before exposure to heat [1]. Fujita said that using crushed ice is particularly effective because it helps lower the deep body temperature more efficiently [1].
Practical applications of the method are being seen in various settings. Shigematsu Tetsunobu, manager of New Leoma World amusement park, said the technique is a way to protect visitors and staff from the elements [1].
Public health reports suggest that even simple actions, such as eating a frozen treat before exercising, can provide an expected effect in preventing heatstroke [2]. The approach is designed for use in homes, outdoor work environments, and public venues nationwide [1, 2].
“Pre-cooling should be performed 20 to 30 minutes before exposure to heat.”
The shift toward pre-cooling represents a proactive rather than reactive approach to heat management. By lowering the thermal baseline of the body, individuals may extend their tolerance for high temperatures, which is critical as Japan faces increasingly severe summer heat waves.
