The FIA has declared a heat hazard at the U.S. Grand Prix, meaning driver cooling systems are expected to be in use for the second race weekend in a row.
Drivers will have the option of wearing a specially-designed cooling vest under their overalls, which helps to keep their body temperature low in the heat of the cockpit.
If drivers opt against using it, ballast is added to compensate for the weight advantage of not running the system, so that those using the cooling system are not at a competitive disadvantage.
The heat hazard warning was declared after the forecast from F1’s official weather service predicted temperatures of 31°C at this weekend’s race in Austin, Texas.
The FIA took the same action in Singapore two weeks ago, with some drivers opting to wear the vest while others chose not to.
The heat hazard rule was introduced in reaction to the 2023 Qatar Grand Prix, which took place in intense heat and humidity.
Williams driver Logan Sargeant retired from the race due to the conditions, while Lance Stroll collapsed by his car after the race, after being on the verge of blacking out in high-speed corners.
There are plans to make wearing a cooling vest mandatory at heat hazard races in 2026, although some drivers have spoken out against compulsory use in the future.
“I haven’t used the vest,” Max Verstappen said after qualifying in Singapore. “I’m also not intending to use it because I feel like this needs to be a driver choice.
“Of course, from the FIA side, they will always throw it on safety, but then we can talk about a lot of stuff that can be improved on safety — including pit entries in certain places. I think that has a bit more priority than a vest in the car because I don’t like it.
“I don’t like the tubes that are on you, on your body, with the belts that go next to you. Then they can say it’s [just] a bad design. I disagree.
“It just needs to be an option for the drivers to choose. Some like it, some don’t, and that’s fine. It should be a personal preference.”
