Japan adds new category to heatstroke index due to dangerous heatwave

To reduce deaths from heatstroke, Japan has added a fourth category, “most severe,” to its heatstroke index, alongside the existing categories of mild, moderate and severe.

The move comes in the same week that six people died from a heatwave with temperatures rising as high as 40 degrees Celsius (104 degrees Fahrenheit) in some parts of Japan, five degrees higher than the level weather officials classify as “extremely hot.” A weather agency official described the severe heat to Agence France-Presse as “rather rare,” especially as it is occurring during the country’s rainy season, which typically runs from May to July.