Kimi Antonelli reveals shock safety failure of controversial F1 device

Kimi Antonelli has conceded to encountering a shock failure of F1's latest safety feature that left him "warming up".

Ahead of this weekend's United States Grand Prix, the FIA declared the event to be a heat hazard given the extreme temperatures at the Circuit of the Americas. The thermometer hit 33°C at the start of sprint qualifying.

For this season, the drivers have the option to wear a new cooling vest through which ice water is pumped to aid comfort.

It is set to become mandatory for next season, although this has become "a polarising subject" for the drivers, according to Williams' Alex Albon, with many believing they should have the option over whether to wear it or not.

Mercedes driver Antonelli wore the vest for sprint qualifying, only for it to surprisingly let him down ahead of being knocked out of SQ2 by just six thousandths of a second to Ferrari's Lewis Hamilton.

"I struggled in the car because I had a few physical issues," said Antonelli, initially referring to the sole free practice session ahead of the sprint shootout.

"But the car felt good to be honest, and I was confident in SQ2. I was wearing the cooling vest, and we had a failure, so instead of cooling, it was warming me up, so I had a big struggle in the session."

Antonelli knows he should have made it into SQ3 but encountered a lock-up on the approach to Turn 3 that undermined his bid to join team-mate George Russell in the top 10.

"I just need to figure out why I suffered so much with locking," said Antonelli. "It is obviously very disappointing because SQ1 felt good.

"But I just struggled with locking. I had two big lock-ups on the lap and lost quite a lot of time.

"I'm disappointed as I had the pace to be in SQ3, but now we will focus on Saturday."