John-Lee Augustyn and Ben Swift are out of the Vuelta a España after illness swept through the Team Sky camp ahead of the third stage.
"If you are trying to race hard in this heat when you're not right it's an absolute nightmare."
Four riders - Simon Gerrans and Peter Kennaugh were the others - and three staff were very sick all through the night and it was touch and go whether they would be able to start the stage from Marbella to Malaga.
Augustyn was forced to abandon the race early on in the 157.3 kilometres route, a brutal setback after what had been a tough season for the 24-year-old South African.
He overcame a niggling knee problem earlier in the campaign, was hit by a virus at the Brixia Tour and also had to travel back to his homeland temporarily due to the conditions of his work visa.
But after regaining full fitness, the specialist climber had been particularly looking forward to the final Grand Tour of the season having achieved many of his best results in Spain.
The sudden onset of the sickness was underlined by Swift's withdrawal around 100 kilometres into Monday's stage; less than 24 earlier he had sprinted into seventh place on stage two and remarked on how good he was feeling.
The 22-year-old was Team Sky's main sprinter in the nine-man Vuelta squad and Sunday's display was the third Grand Tour top 10 finish of his fledgling career.
Team principal Dave Brailsford felt huge sympathy for both riders, saying: "It's a massive blow for John-Lee and for Swifty too, a guy who's really started to show good form. For him to lose out now is a real, real shame.
"Ben had even said he felt great yesterday - it just came on during the night; they had fevers and were throwing up everywhere.
"John-Lee had literally just started the race today but couldn't ride his bike anymore. It was 36 degrees again and if you are trying to race hard in this heat when you're not right it's an absolute nightmare.
"It's affected the staff and riders - we've all but ruled out food poisoning," added Brailsford. He explained: "The riders eat completely different meals to the staff so it's a strange one because everyone is vigilant with the hand gels and sterilising things thoroughly.
"It could account for a lot really because we had some staff in Seville who weren't great, so whether they've picked up something from them, who knows."