Lausanne - The marathon and race walks at the 2020 Tokyo Olympics could be moved from the Japanese capital to Sapporo where temperatures will be "significantly lower", the International Olympic Committee said on Wednesday.
The IOC is proposing the move because temperatures in Tokyo during the July 24-August 9 Games could reach into the high 30s Celsius.
In Sapporo, more than 800 kilometres (500 miles) further north, they would be five to six degrees cooler during the day.
"Athletes' health and well-being are always at the heart of our concerns," IOC President Thomas Bach said in a statement.
"The new far-reaching proposals to move the marathon and race walking events show how seriously we take such concerns.
"The Olympic Games are the platform where athletes can give 'once-in-a-lifetime' performances, and these measures ensure they have the conditions to give their best."
The plan to change the location of the events has yet to be rubberstamped.
The initiative will need the backing of all of the major stakeholders, notably the host city Tokyo, the national Olympic committees and the relevant broadcasters.
The IOC Coordination Commission for Tokyo 2020 will dedicate a special session in its meeting in Tokyo at the end of the month to measures to deal with the heat.
When Tokyo last hosted the Olympics in 1964 the marathon -- won by the great Ethiopian Abebe Bikila -- was run at 1:00pm but that was in the month of October, not August as will be the case next year.
At the recent world championships in Doha, both the men's and women's marathons started at midnight but the heat and humidity still presented massive problems.
Ruth Chepngetich won the women's race in a sluggish 2:32.41 -- 17 minutes outside Paula Radcliffe's then world record -- while 28 of the 68 starters failed to finish.
The men's race was held in cooler conditions but Lelisa Desisa's winning time of 2:10.40 was over nine minutes slower than the world record.
"We have been working closely with the IOC and Tokyo 2020 on the potential weather conditions at next year's Olympic Games and will continue to work with the IOC and Tokyo 2020 on the proposal to move the road events to Sapporo," said International Amateur Athletics Federations' President Sebastian Coe.
"Giving athletes the best platform for their performances within the environment they are in is central to all major events.
"We will work with the organisers to create the very best marathon and race walk courses for next year's Olympic Games."
The planned relocation of the marathon and race walks are a part of a broader scheme to lessen the effects of the weather on the athletes.
The 5,000m and longer-distance races are being scheduled for the evening athletics sessions and not in the morning sessions while all rugby sevens morning games are slated to finish before 12:00.
The mountain bike start time has been pushed back to start at 15:00.
The IOC said that the timing of other events and competitions would be "kept under review".