The Japanese Association for Acute Medicine has urged people not to go outdoors unless absolutely necessary during the hottest hours of the day.
The association raised the alert on Monday as wide parts of Japan are experiencing oppressive heat, with temperatures soaring to 35 degrees Celsius or higher.
During an online news conference, the association’s director, Yokobori Shoji, who is also a doctor at Nippon Medical School, said people are more susceptible to heatstroke when their bodies have not yet gotten used to the heat.
Yokobori said people should pay attention to those who are especially at risk, such as the elderly, children, those with underlying health issues or disabilities and people who cannot afford air conditioners.
The association has reviewed its classification of heatstroke severity, adding a new category, “most severe,” which indicates a high risk of death.
People with a core body temperature of 40 degrees Celsius or higher who are unconscious or in a state of decreased consciousness fall under this category.
For these patients, the association recommends quick and intensive treatment using “active cooling” methods, such as placing them in cold water baths.
Yokobori said the summer heat in recent years is sometimes described as reaching “disaster” levels, and the number of heat-stricken patients could exceed those affected by natural disasters. He said the association will further consider what kind of system is necessary to help heatstroke patients.