Formula One drivers on Sunday declared the Qatar Grand Prix as the toughest physical test of their career, some calling for a review of its October date in the calendar, after a gruelling race that saw several vomiting in their helmets and some taken to the medical centre afterwards.
American Logan Sargeant of Williams retired after 40 laps after complaining that he felt too sick to continue, suffering severe dehydration and having vomited.
His team chief James Vowles said he felt a responsibility for his drivers' health and advised him to retire.
"Let's bring it in and call it a day," he said. "Let us look after you. There is no shame in retiring."
Frenchman Esteban Ocon completed the full race distance in seventh place for Alpine.
Afterwards, he said he had "thrown up" on laps 15 and 16 and felt ill, but had managed to re-focus mentally and continue.
"I was mentally fighting to focus... I have never in the past had any experience like. I prepare to race for two race distances, but this was too much for me," he said.
"It must have been 80 degrees in the car (Celsius)... It was my hardest ever race and the toughest four points I've won."
He said he had tried to cool down by diverting airflow to his face and body with his hands while racing on the straights.
Ferrari's Charles Leclerc, who finished fifth, said: "That was the toughest race of my career and I think it is the same for all of us.
"The heat was crazy. It is a high speed circuit, with high speed corners which is harder for us and thirdly we had to make three pit-stops for the tyres.
"If felt twice as bad as Singapore. It was right on the limit even for us and we are all prepared for this. We have to consider this race's place on the calendar at this time of the year."
Next year's Qatar event is scheduled, like the 2022 football World Cup, for December.
'Burnt by this heat'
Fernando Alonso, at 42 the most widely-experienced driver on the grid, compared it with the races he endured in Malaysia, with daylight starts, and in Bahrain.
This was only the second Qatar race. The first in 2021 was held in late November.
Alonso said: "I asked my team on the radio if they would tip water over me in a pit-stop, but it was not allowed. My seat was burning hot and felt my right side was burnt by this heat.
"We have to think for the future –- maximum temperatures or maximum humidity... In football, they have water breaks, but we can't have that, can we?"
The triumphant triple world champion Max Verstappen agreed.
He said it was one of the toughest races he had experienced. "In the top five," he said.
George Russell of Mercedes said it was "as hot as an oven".
"Sometimes I train deliberately in a sauna, but today after 12 laps I wanted to get out of the car," said the Briton.
"It was at least 50 degrees or more and we are wearing fireproof race overalls and we had extra fast laps with the pit stops... It was too much. But it is the sport I love."
At least three drivers were reported to have gone to the medical centre for rehydration treatment after the race.