Aerial view of Marina Bay, Singapore, 2024

The FIA has applied Formula 1’s new “heat hazard” rules for the first time at the Singapore Grand Prix.

The regulations have been applied because the official weather forecast for the weekend indicates temperatures will exceed 31C during Sunday’s grand prix. The FIA therefore requires teams to add the Driver Cooling System to their cars for the duration of the weekend.

Drivers may opt out of wearing the driver cooling apparatus. However all cars must comply with a higher minimum weight limit this weekend irrespective of whether their drivers attach the cooling system to their overalls.

Under the heat hazard rules, the minimum mass limit for cars this weekend will rise by 5kg to 805kg for the grand prix.

The rules were introduced following the extreme conditions drivers experienced at the Qatar Grand Prix in 2023. Air temperatures reached 32C during the race but cockpit temperatures were significantly higher. Esteban Ocon vomited in his car during the race and Logan Sargeant withdrew due to heat exhaustion.

Some drivers have questioned the need for the heat hazard rules. “I don’t think we need an [air conditioning] unit in the car,” said Lewis Hamilton last year. “This is Formula 1, it’s always been like this. It’s tough in these conditions and we’re highly-paid athletes. You’ve got to train your ass off to make sure you can withstand the heat, ultimately. And it’s tough. It’s not easy, especially when you go to places like Qatar and Singapore.”

The Singapore Grand Prix is typically held in hot and humid conditions and has been disrupted by powerful thunderstorms which often develop in the area. Rain greeted the teams on Thursday ahead of the start of practice tomorrow.

More rain is forecast on Friday and Saturday but is expected to clear up before the track action begins in the evening. Sunday is forecast to be dry with temperatures up to 32C.

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F1’s new heat hazard rules

Sporting regulations: Heat hazard

26.19 If the Official Weather Service predicts that the Heat Index will be greater than 31.0°C at some time during the sprint session or the race at a Competition, or at the sole discretion of the Race Director, a Heat Hazard may be declared twenty-four (24) hours prior to the scheduled start of the Competition. Once a Heat Hazard is declared it shall remain in force for the Competition. All competitors will be notified via the official messaging system. Once a Heat Hazard is declared:
a) All components of the Driver Cooling System, with the exception of any cooling medium and any items of a driver’s personal equipment that form part of the system must be fitted.
b) At the start of any sprint session or race for which a Heat Hazard has been declared, all components of the Driver Cooling System must be fitted. The system must be functional and available for use by the driver, meeting the specific provisions provided in Article 14.6.1 of the Technical Regulations for these sessions.
However, any driver may elect not to wear any items of personal equipment that form part of the driver cooling system. In such circumstance, all other components, including any cooling medium, of the Driver Cooling System must be fitted. In addition, the difference in mass between the driver’s personal equipment normally used and any items of a driver’s personal equipment that form part of the system must be compensated by the fitting of 0.5kg of ballast in the cockpit, such ballast designated for this purpose will be included in sum of masses described in Article 4.7b of the Technical Regulations.
c) In accordance with Articles 4.1 and 4.7 of the Technical Regulations the Heat Hazard Mass Increases shall apply.

Technical regulations: Heat hazard

4.1 Minimum mass
The mass of the car, without fuel, must not be less than 800kg plus the Heat Hazard Mass Increase (defined in Article 4.7), at any time during the Competition.
If, when required for checking, a car is not already fitted with dry-weather tyres, its mass will be determined using a set of dry-weather tyres selected by the FIA technical delegate.

4.7 Heat Hazard Mass Increase
During a Race or Sprint Session for which a Heat Hazard has been declared:
a. A Heat Hazard Mass Increase of 5kg will be applied.
b. The sum of the masses of the following items must be no less than 5kg;
i. The difference in mass between the driver’s personal equipment normally used and that used for a Heat Hazard session.
ii. The mass of any driver cooling system not included in (i) above.
During any Free Practice, Sprint Qualifying or Qualifying Session for which a Heat Hazard has been declared:
c. A Heat Hazard Mass Increase of 2kg will be applied.
d. The mass of the driver cooling system must be no less than 2kg.

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Technical regulations: Driver Cooling System

14.6 Driver Cooling System
14.6.1 The driver cooling system is defined as a system, the sole purpose of which, is to provide additional cooling for the driver.
The driver cooling system may use the phase change of a substance in its operation.
During a Race or Sprint Session for which a Heat Hazard has been declared;
a. A system that uses a continuous process must be capable of extracting heat from the driver at a rate of at least 200W with an ambient temperature of 40°C.
b. A system that uses stored thermal energy must have a reserve of at least 1.1MJ, calculated with the final reservoir temperature below 10°C.
14.6.2 Any energy stored exclusively for the Driver Cooling System and only fitted when the Driver Cooling System is fitted, will not be considered part of the Non-ERS Energy Stores defined in Article 5.3.2.
14.6.3 Any refrigerant must have a Global Warming Potential of less than 10.
14.6.4 Solid CO2 (dry ice) must not be used in the driver cooling system.
14.6.5 The cooling medium within the driver’s equipment may only be air, water, or (in exception to Appendix L Chapter III Article 2) an aqueous solution of sodium chloride, potassium chloride or propylene glycol.
14.6.6 Subject to the approval of the FIA, parts of the driver cooling system may be placed within RV-CH-MID-STRUCT, in exception to Article 12.3.5, within RV-COCKPIT-DRIVER, in exception to Article 12.5.4., or within the lower 50mm of the volume defined in Article 12.5.4.a (but not within the volume defined in Article 12.5.4.b).
14.6.7 For the sole purpose of supplying air to a heat exchanger which is part of the driver cooling system, an additional aperture may be made, or an existing aperture enlarged, with a total increase in aperture area of 1000mm2, either in the area defined in Article 3.5.8. or in the area defined in Article 3.6.1.f.
14.6.8 The following fans are permitted:
a. A fan of up to 12W for the sole purpose of drawing air through the condenser of a refrigeration system.
b. A fan for the sole purpose of feeding cooled air into the driver’s overalls.
14.6.9 Parts of the thermal store for the driver cooling system which are in the volumes defined in Articles 13.5.1.d or 13.6.3.f must be homologated as follows.
The Thermal Store:
a. complete and filled with coolant, must be cooled to its minimum operating temperature.
b. must be placed between the platens of a compression testing machine. The platens must be large enough that the parts of the Thermal Store within the specified volume remain between them throughout the test.
c. must be orientated so that the test direction is aligned with the Y-Axis for components [placed] in the volume defined Article 13.5.1.d or the X-Axis for components [placed] in the volume defined Article 13.6.3.f.
d. must be crushed until the distance between the platens is less than 25mm.
During the test, the load must not exceed 20kN

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