Eleven people were killed and nearly 6,000 hospitalised in Japan due to heat-related illnesses last week, the government said on Tuesday.
The heatwave saw 5,664 people taken to hospitals, 1,199 of whom displayed severe symptoms requiring being admitted for at least three weeks of treatment, and 1,792 requiring shorter treatment for less serious symptoms.
The total number, however, has spiked from the almost 2,000 people hospitalised across Japan a week earlier due to the heat.
In the week to Sunday, the Fire and Disaster Management Agency said that 52.6 per cent of the total people sent to hospital were seniors aged 65 and older.
Aichi Prefecture saw the most people rushed to hospital with 393 cases, followed by Osaka Prefecture with 388 cases.
Tokyo, meanwhile, saw 299 people rushed to hospital suffering from heat-related medical conditions.
On Tuesday, temperatures continued to soar, with the agency and weather officials warning people to take preventative measures against heatstroke and other heat-related illnesses.
Tajimi in Gifu Prefecture, central Japan, saw the mercury rise to 37.1 degrees Celsius, while Kumagaya in Tokyo’s neighbouring prefecture of Saitama and Kyoto saw temperatures rocket to 36.8 degrees Celsius.
In the capital city of Tokyo, the daytime high was logged at 35.4 degrees Celsius, with temperatures across Japan expected to stay above 25 degrees Celsius overnight.
Across wide swathes of Japan from north to south, temperatures are forecast to remain upwards of 36 degrees Celsius through Wednesday, weather officials said.