Singapore Grand Prix declared heat-hazard race as Indonesian smog shrouds Marina Bay
Marina Bay braced for brutal conditions
The Singapore Grand Prix has been declared a heat-hazard race — the second consecutive weekend Formula 1 has deployed the designation and the fourth time this season.
The status, first introduced in 2025, applies to any event where temperatures are forecast to exceed 31C at some point during the race. It allows teams to fit cooling devices that pump liquid through a vest worn by the driver to manage cockpit temperatures.
Haze from Indonesian fires adds to the strain
This year's race is also being held amid air-quality issues caused by smog from fires in Indonesia. F1 is monitoring the situation — which also applied at last weekend's Bahrain Grand Prix in Malaysia — but does not currently consider it a cause for major concern.
Singapore, which made its F1 debut in 2008, sits close to the equator and has long been regarded as one of the most physically demanding rounds on the calendar. Temperatures across the race weekend sit in the 31-33C range, with high humidity and a daily chance of rain. Although the race is run at night, temperatures still hover around 30C even after dark.
The toll is well documented: in 2024, George Russell and Lewis Hamilton were treated for heat exhaustion after the race.
Cooling kit optional — but with a catch
The cooling kit is not mandatory. Any driver who chooses not to use it must carry 5kg of ballast to remove any competitive advantage. The system uses a cooling tank and pump, usually situated in the car's nose, that delivers a cooled liquid such as glycol through pipes in a fireproof top worn beneath the overalls.
It is not unusual for temperatures inside an F1 cockpit to rise above 40C. Teams and drivers cite two key compromises for avoiding the system: the liquid is difficult to keep cool for an entire grand prix — a problem worsened in Singapore, the longest race of the year — and some drivers find the cooling top uncomfortable in the tight confines of the cockpit. If the liquid warms up, it reverts to car temperature, which is considerably higher than ambient.
Verstappen and Leclerc split on the vests
Red Bull's Max Verstappen said: "For me, it's not needed. Yes, it's hot, but it's not sauna. And with this cooling vest, you have these stupid cables in your car, so it's just limiting your movement as well.
"Even if it would work for one and a half hours, like cool, cool, I don't need it. It doesn't work anyway for one and a half hours. I've never had it in any category that has worked for one and a half hours."
Ferrari's Charles Leclerc added: "Ideally, if I can have an even better cooling vest, I will always take it. Let's say that for 15-20 laps it works pretty well. But then after, for the rest of the race, you are quite warm, just like you are without the cooling vest. So at least I'm getting 15-20 laps, and I'm already grateful of that.
"It's not that I feel like every driver on the grid is not physically fit to do a whole race. However, to be at your 100% at the end of a race, or from the middle of the race here, where you lose so much water and you are dehydrated, for sure we leave something on the table there."
Mercedes opt out as FIA offers cost-cap relief
Mercedes are among the teams that have decided against running the system, preferring to devote the resources required to make it robust enough to last a race into car performance instead. The FIA has granted teams a cost-cap allowance of $50,000 (£38,000) if they can produce a system that keeps the liquid cool for an entire grand prix, and a further $75,000 (£57,000) if they can make the top comfortable.
Mercedes deputy team principal Bradley Lord described the allowance as "small", adding: "We didn't believe that allowance was sufficient for us to be able to develop a solution that would be robust enough to last for the entire race."
Singapore follows the Austrian and Italian Grands Prix — both staged amid the Europe-wide heatwave that produced record temperatures — and last weekend's Bahrain Grand Prix in Malaysia in being declared a heat-hazard race this year. The conditions in Malaysia and Singapore are comparable with typical south-east Asian temperatures, and had the designation existed before 2025, both would have qualified on numerous past occasions.