Fernando Alonso believes changing wind conditions leading into the Qatar Grand Prix could have been a factor behind the extreme heat faced by drivers.
The FIA has launched an investigation into the Lusail race after drivers struggled to physically cope with the demands of the race - with Esteban Ocon being sick in his helmet while Lance Stroll admitted to losing consciousness behind the wheel.
It was brought about by a combination of factors, including flat-out pushing made possible by the 18-lap stint lengths imposed by Pirelli and the FIA, high G-forces with only one corner below 100kph, and no Safety Cars after the opening lap.
Such conditions were not found during the Sprint race, with three Safety Cars in the 19 lap affair, but Alonso - who finished sixth - feels a change in the wind conditions had a part to play in the battering experienced by drivers.
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Alonso's hottest races
"It was a surprise to be honest, because [Saturday] was not that bad, maybe it was windy or something [and in the race], we missed that ventilation, so it was extreme," Alonso told media including RacingNews365.
"We need to see if in the future, there is any solution and in such extreme conditions, if we can agree on delaying the start or whatever.
"I think it was one of the hardest races [of my career] for sure.
"When we were racing in Malaysia, at Sepang in the daytime, I remember that to be very extreme, Bahrain 2009 I think was 41 degrees
"That one was extremely hot and this one for sure has to be in the top three [hottest races of my career]."