A DEADLY heatwave in Japan has prompted questions over the wisdom of staging the 2020 Olympics in July and August.

Nine people died and thousands were taken to hospital across the country on Wednesday as temperatures rose as high as 40.7C in central Japan.

Rescuers in Tokyo responded to more than 3000 emergency calls, breaking the record of 2900 set the previous day. A total of 317 people were taken to hospital.

The 2020 Olympics will run from July 24 to August 9, when temperatures in central Tokyo can exceed 35C. Tokyo’s Application File to host the 2020 Games reads: “The pleasant weather conditions at this time of year will be ideal for athletes.”

But experts have warned the risk of heatstroke in Tokyo has escalated in recent years, while noting the Games are expected to take place in conditions when sports activities should be halted.

In 1964, the Olympics in Tokyo were held in October, mostly to avoid the scorching heat, but that was before the Olympics became big business and TV contracts determined schedules.

Authorities plan to lay pavements that emit less surface heat and plant taller roadside trees, but many worry it will not be enough.