Two-year countdown begins with sweltering temperatures and unfinished main stadium

TOKYO - The heat is on for the Japanese capital's effort to host the world at the 2020 Olympics.

Since being awarded the Games, which will be the largest ever with 33 sports and 339 events, Tokyo organizers have had to deal with a series of setbacks ranging from stadium and construction delays, natural disasters and a mascot scandal.

It was all brought sharply into focus this week with a deadly heatwave gripping Japan as the countdown clock ticked down to two years until the July 24-Aug 9 Olympics.

The potential for scorching summer conditions has always concerned organizers, with temperatures in central Tokyo often exceeding 35 Celsius (95 Fahrenheit) in July and August, made more difficult because of high humidity.

This summer heatwave has resulted in more than 80 deaths and sent tens of thousands to hospitals.

The temperature reached an all-time high on Monday when local media reported the 41.1 Celsius (106F) was the hottest ever recorded in Japan.

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

"We are mindful that we have to prepare for extreme heat," John Coates, head of the IOC's coordination commission for the Tokyo Games, told a recent media conference.

The 1964 Games in Tokyo were held in October to avoid the harshest heat, but that was before the Olympics schedule was influenced by rights-paying TV networks and sponsors.

Local organizers for 2020 are doing what they can to help athletes combat the conditions. The marathon and some other outside events will be held early in the morning to avoid extreme heat.

The federal and Tokyo metropolitan governments are also planning to lay pavement that emits less surface heat and plant taller roadside trees for shade.

"The spectators as well as the athletes have to be taken care of," Coates said.

"The timing of the marathon and road walks will be as early as possible to beat the heat."