Decathlon star Kevin Mayer has slammed the decision to stage the World Athletics Championships in Doha on Saturday, accusing organisers of putting athletes "in jeopardy."
The 27-year-old - Olympic silver medalist in 2016 - said staging the championships in the heat and humidity was a "catastrophe".
"We can all see it's a disaster, there is no-one in the stands, and the heat has not been adapted at all," he said.
"There have already been nearly 30 withdrawals in the women's marathon. It's sad.
"We have to leave reason aside and more concentrate on the passion, because if not I would have boycotted these championships.
"We haven't really prioritised athletes when organising the championships here. It makes it difficult."
Mayer was speaking after 28 of the 68 runners in the women's marathon failed to finish after wilting in weather conditions of 32 degrees Celsius and humidity of over 70%.
His stinging comments follow those of 50 kilometres walk defending champion Yohann Diniz, who accused the IAAF of treating athletes as 'idiots' for making them compete in such conditions.
Diniz added the walkers were being used as "guinea pigs".
"Clearly by organising the championship here, they didn't put the athletes first, they've mostly put them in jeopardy," said Mayer at a press conference.
"Now, it's up to us to not act like princesses and to get on with it anyway but for sure, we're not at all in the right conditions to perform."
Mayer, whose own defence of the title he won in London gets started on Wednesday, made no bones about what he thought about the championships.
He accused the organisers of not adapting the heat inside the Khalifa Stadium, although it has been through state-of-the-art cooling system.
"Even if people aren't saying it out loud, it's obvious it's a catastrophe," he said.
IAAF says one athlete hospitalised
One runner competing in the women's marathon that took place in scorching heat was hospitalised following the event but later released, the IAAF said on Saturday.
The global governing body of athletics said the athlete, whose identity was not disclosed, had been kept under observation in hospital while 30 other runners sought precautionary medical treatment after the race.
There were no cases of heat stroke among the 68 competitors, "despite very challenging weather conditions for endurance events," the IAAF said in a statement.
"In the women's marathon 68 competitors started and 40 finished – which is comparable to the completion rate at previous World Championships in Tokyo (1991) and Moscow (2013)," the IAAF added.
Some marathon runners said they thought the race should not have been run because of the extreme weather conditions.
The IAAF also said the men's and women's 50km race walking events starting at 23:30 on Saturday would go ahead as planned.
The temperature is expected to be at or below 29 degrees Celsius, it said.
Marathon was an absolute farce this morning with people dropping out left, right and centre and now we've a World Cup in 2022 in the same country. Why are top class athletes subjected to these conditions? Shocking & embarrassing
— JFK Sports Physio (@JFKsportsphysio) September 28, 2019
What was IAAF thinking when they scheduled the marathon? 33 degree heat in Doha would feel like 120 degree heat of Arizona. You can cook a cheese pizza right outside your home. https://t.co/Rzc1SvH2GS
— Bilal Khan ﷽ (@Peace4allpak) September 28, 2019
70 of the best female marathon runners in the world started the world championship marathon in Doha and only 40 finished the race, ridiculous heat and humidity, have to think about people's immediate and long term health putting people's lives at risk like that! Disgusting
— Lewis Thompson (@LewisThompson7) September 28, 2019
I've been to Doha and I can attest to the heat. Who in their right mind thought Doha should be the place of this Marathon? The heat there is disgusting and its humid on top of the heat.
— Gary Grubb (@thegrubbshow) September 28, 2019