Japanese authorities and medical experts are urging special caution against heatstroke as scorching conditions continue in eastern and western Japan.
Weather officials say the mercury soared in wide areas of Japan on Thursday as powerful high-pressure systems brought punishing heat.
Kyoto City marked 39.8 degrees Celsius, the day's high on the archipelago, by 4:30 PM. Hirakata City in Osaka Prefecture had a high of 38.9 degrees.
Medical experts warn that the intense heat can be life-threatening. They advise people to refrain from exercising outdoors during the day and to use air conditioning. They also advise frequently drinking water and taking salt.
Experts say people in areas hit by torrential rain and floods this month should be extra cautious as harsher living conditions have added to risks of heatstroke.