Doha - Decathlon star Kevin Mayer 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".
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 (90 degrees Fahrenheit) 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 - who added the walkers were being used as "guinea pigs" - defends his title later on Saturday, both the men and women's races get underway.
"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 on Saturday.
"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.
"There is no one in the stadium, the heat is not at all adapted, yesterday we saw about 30 people drop out of the marathon, it's sad.
"Afterwards, I think at times like this you have to replace reason and focus on passion, otherwise I would have boycotted this championship.
"But clearly I am here and I'm only focused on the decathlon and not everything else. "