Singapore has long been the most physically taxing Formula 1 race of the year thanks to a combination of a challenging stop-start circuit and high levels of heat and humidity. Now this year's weekend in the city-state has become the subject of F1's official Heat Hazard.
The ambient temperature is expected to reach 31C on both Saturday and Sunday, which is the FIA's threshold for declaring a Heat Hazard. Race director Rui Marques notified the teams of this on Thursday.
Now the teams have two options: either their drivers must wear the mandatory cooling vests or their cars must carry more ballast.
Whether the drivers elect to use the vests or not, the rules state that their cars must be fitted with the necessary equipment to make the vests work – specifically the pumps, coolant reservoir and heat exchanger.
Any driver then choosing not to wear a vest must carry additional ballast.
The rules on this are clear: "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."
