Tokyo, Aug 6 (IANS): Fifty-seven people have died due to heat-related medical issues in Japan since last week, the government said on Tuesday, with the number of those taken to hospitals more than tripling to 18,347 from the previous week's 5,664.

The weekly figure for hospitalizations due to high temperatures was the second highest since tallies began in 2008, according to the Fire and Disaster Management Agency.

Of the 18,347 people, 729 had severe symptoms, while 6,548 had less serious issues, requiring shorter stays. Those aged 65 and older accounted for 54.3 per cent of the total, the Japan Times reported.

Tokyo had the most people taken to hospitals at 1,857, followed by 1,342 in Aichi Prefecture and 1,307 in Saitama Prefecture.

Deaths were reported across 24 prefectures, with Hokkaido seeing the most at seven, followed by five each in Ibaraki and Saitama.

A high pressure system over the Japanese archipelago preserved extreme heat, said the agency.

It advised people to constantly stay hydrated and rest in cooler areas.