World Athletics president Lord Sebastian Coe has acknowledged the World Championships will face "some heat challenges" when competition gets underway on Saturday in Tokyo.
Japan has endured a stifling summer of record-breaking heat over the past month, with 15 cities recording their highest temperatures since records began in 1898.
During August, 44 of the country's 47 prefectures issued heat stroke warnings, while temperatures in Tokyo were expected to hit 30 degrees Celsius on Saturday, with 75 per cent humidity.
On Sunday, that temperature will rise to a predicted 34C.
Unlike at the Tokyo Olympics in 2021, long-distance walking events and the marathon will take place in Tokyo at the World Championships, with the 35km race walk starting at 8am local time (9am AEST) on Saturday.
The women's and men's marathon are also scheduled to start at 8am on Sunday and Monday, respectively.
At the pandemic-delayed Games, those events took place in Sapporo to the north to negate the heat.
"I don't think it's any great secret, we do have some heat challenges in Tokyo," Coe said at a press conference on Tuesday.
"I'm very proud to be able to say, with full justification, that we have the most accomplished and the most capable health and science team in any international sport and frankly, any sporting organisation.
"That shouldn't come as a surprise because we have been dealing with some of these challenges for a long time."
Coe said sport was having to take the lead on climate change issues, taking aim at world leaders for their inaction.
"Some of you have heard me talk about the challenges of climate change. These are not transient. They're here to stay," Coe, the British two-time Olympic 1,500m champion in 1980 and 1984, said.
"Governments have not stepped up to the plate, and sport is going to have to take some unilateral judgements and decisions here.
"If we are committed to athlete welfare, then we should probably be openly committed to that."
He added that international sport as a whole will have to "revisit" the global calendar to account for rising temperatures and admitted that there may need to be some flexibility if conditions worsened in Tokyo.
"If we are committed to athlete welfare, then it is inevitable that we are going to have to stage some of our endurance-based events maybe at times of the year that are going to give optimum chances for the athletes, and not leave them in a health or a performance deficit," Coe said.
"But what I can say is that we have the right people in place in Tokyo, and the right discussions taking place if we had to make any adjustments to the timetable in advance of those scheduled events because of these conditions."
