F1 Singapore: Heat Hazard declared, cooling vests required on board

The FIA has declared a Heat Hazard for the sprint and the Singapore Grand Prix in Formula 1. Cars must therefore carry the driver cooling system. It is the fourth such declaration of the 2026 season, and the subject is already dividing the paddock before first practice at Marina Bay.

Why the FIA declared a Heat Hazard

The decision, dated 8 October 2026, was taken by race director Rui Marques. The official weather service forecasts a heat index above 31°C at some point during the sprint or the race. The trigger is Article B1.5.10 of the 2026 F1 regulations. Every car must then carry the components of the approved system for the sessions concerned.

The principle: a pump circulates cooled fluid through tubing in a fireproof garment worn under the driver's race suit. The system was introduced after the 2023 Qatar Grand Prix, where several drivers needed medical attention. F1i recalls that cockpit temperatures there reportedly approached 50°C and that Logan Sargeant retired with heat exhaustion. Singapore combines heat, high humidity, a long race, little airflow on a street circuit and a night start.

Drivers split

According to F1i, development of these systems falls outside the cost cap and the designs are open, so teams can copy existing solutions.

• George Russell (Mercedes): Mercedes has not put engineers into a viable unit for its 2026 car, yet he sees a clear benefit.
• Carlos Sainz (Williams): he praises his team's vest, which helps him and Alex Albon.
• Isack Hadjar: he would like the technology banned because F1 is supposed to be tough.
• Max Verstappen: he considers the vest unnecessary, the cables restrict movement, and the cockpit is hot but "not a sauna".

What to watch in Singapore

For F1i, a majority of the grid will not rely on this technology despite the extreme humidity. Albon and Russell say heat affects performance and focus, but the effect on lap times is hard to quantify.

Key points

• Heat Hazard declared for the Singapore sprint and Grand Prix.
• Threshold: forecast heat index above 31°C.
• Fourth declaration of the 2026 season.
• Drivers are split on the vest's usefulness.