Austrian Grand Prix declared heat-hazard race by Formula 1's governing body the FIA

Austria is the first race this year to be declared a heat hazard, amid a heatwave across Europe that is establishing record temperatures in many countries, including the UK.

The rule was first introduced last year, when the Singapore and US Grands Prix ran under the designation.

Some drivers prefer not to use the cooling kit because of discomfort, and because there have been issues with the coolant running out before a grand prix is finished, in which case the liquid ends up at car temperature, which is considerably higher than ambient.

Temperatures in the cockpit of an F1 car can be more than 40C, and drivers are wearing several layers of fireproof clothing in addition to a balaclava and helmet, so overheating is a serious concern.

Red Bull's Isack Hadjar said: "I really don't like it - too many tubes, too many things in the cockpit.

"It works really well for, like, 10 minutes and then it's warm again. I have never been to a point where I really needed the vest."

But McLaren's Oscar Piastri said he will likely use it this weekend.

"I used it a couple of times last year," the Australian said. "There is the risk that if it fails, it's worse than not wearing it, but if you get the system working well it can help a bit.

"It's not a complete game changer but it is personal preference. If you can get it to work and it cools you down a little bit, you might as well."