For the first time in Formula 1’s history, a “heat hazard” warning has been issued — and fittingly, it comes at one of the sport’s most gruelling circuits: Singapore. Ahead of the 2025 Singapore Grand Prix, the FIA announced the new alert system as temperatures are expected to soar past 30°C with humidity levels exceeding 70%. The result? Teams and drivers are being forced to make difficult choices before even hitting the track.
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What Exactly Is a “Heat Hazard”?
The “heat hazard” system is a new FIA initiative, formally introduced under Article 26, Paragraph 19 of the F1 Sporting Regulations. It acts as an official warning when the combined heat and humidity index is expected to surpass 31°C — a threshold where the risk of dehydration, fatigue, and even heat stroke becomes dangerously high.
Once activated, the heat hazard stays in effect until the end of the weekend, requiring teams, drivers, and medical personnel to take additional precautions. The FIA implemented this system after several drivers suffered from extreme heat conditions during the 2023 Qatar Grand Prix — some vomiting, others collapsing, and most requiring medical treatment after the race.
This new measure signals F1’s growing emphasis on driver health and safety in increasingly hostile climates — a challenge that’s only getting tougher as the calendar expands across hotter regions.
How Teams and Drivers Must Adapt
Once the heat hazard warning is triggered, drivers are presented with two choices:
Wear a cooling vest, or
Add 0.5 kg of ballast to their car.
This rule ensures parity between those opting for the vest and those who don’t — preventing any unfair advantage in terms of weight distribution. Regardless of the choice, every car must be fitted with an FIA-approved cooling system that includes a pump, coolant reservoir, and heat exchanger.
Initially, the FIA considered making the cooling vest mandatory, but after multiple tests and driver feedback, it became clear that comfort and cockpit space were major issues. The vest added unwanted bulk to an already cramped environment. As a compromise, it’s now optional — but every driver must carry the same extra weight if they choose not to wear one.
The Cooling Vest: How It Works
The FIA-approved cooling vest is no gimmick. It’s a technical piece of gear that circulates chilled liquid through tubes woven into flame-resistant underwear. The system connects to a small control unit within the car that regulates temperature, preventing the driver’s core body temperature from climbing dangerously high.
The aim is simple: keep drivers alert and prevent dehydration, dizziness, and muscle fatigue — all of which can impair reaction times and concentration. Until now, drivers have relied on ice packs, cold towels, and heavy hydration routines before the race. With this new system, F1 enters a more controlled phase of thermal management.
Why Singapore Was the Breaking Point
If any race was going to trigger F1’s first “heat hazard,” it had to be Singapore. The Marina Bay circuit has long been infamous for its punishing humidity and oven-like cockpit conditions, with temperatures inside the cars often reaching 55–60°C. Even the most conditioned drivers finish the race utterly drained, often losing 3–5 kilograms of body weight through sweat alone.
This weekend’s conditions are expected to be even harsher than usual, prompting the FIA’s new system to be activated. It’s also a real-world test for the technology — and a glimpse into how Formula 1 will handle the growing impact of climate extremes on its races.
What This Means for the Future of F1
The heat hazard rule could soon become a regular part of F1’s safety framework. With several races held in tropical or desert climates, managing driver well-being is now a performance factor as much as a medical one. The FIA’s move highlights a broader acknowledgment that as cars get faster and schedules get tighter, the human element can’t be pushed beyond its limits.
If the Singapore Grand Prix goes smoothly under these new rules, we could see further enhancements — from advanced cooling systems to adaptive race-day formats when temperatures spike. Either way, this is a landmark moment for Formula 1’s approach to safety, innovation, and realism in dealing with environmental challenges.
