The Singapore Grand Prix has been designated a heat-hazard race, marking the fourth time this season Formula 1 has used the classification and the second consecutive weekend following Malaysia. The official status applies when temperatures are forecast to exceed 31°C at any point during the race weekend.
The designation allows teams to fit cooling devices that pump liquid through vests worn by drivers to manage cockpit temperatures. Singapore joins Austria, Italy and Malaysia in receiving heat-hazard status this year, though the classification would have applied to Singapore many times historically given its typical 31-33°C temperatures.
Any driver choosing not to use cooling equipment must carry 5kg of ballast to ensure competitive fairness. The system uses cooling tanks and pumps to deliver chilled liquid through fireproof tops, though effectiveness diminishes over race distance and some drivers find the equipment uncomfortable in tight cockpit confines.