The 2023 Qatar Grand Prix was catastrophic. While thankfully nobody got injured, all drivers complained about the extreme heat they suffered in the cockpit. Logan Sargeant retired due to heat stroke and dehydration, Esteban Ocon vomited twice in his helmet, and other drivers like Lance Stroll and Alexander Albon required medical attention after the race. George Russell said he was close to losing consciousness while driving.
As a result, FIA introduced a new regulation, called as the Heat Hazard regulation, to invoke when heat temperatures pose a serious threat to drivers. That rule has been declared for the first time today, for the Singapore Grand Prix this weekend.
"Having received a forecast (...) predicting that the Heat Index will be greater than 31 °C at some time during the race at this event, a Heat Hazard is declared", FIA said on Thursday in a statement. With humidity, drivers can expect perceived temperatures of up to 50ºC in the cockpit.
As a result, drivers will be allowed to wear a cooling vest, with tubes where cool air flows. If they choose not, they will have to add extra ballast (around 0.5kg) to their cars as to not have unfair advantage with a lighter car. These vests, which will become mandatory for hot conditions for next season, have not been well received by some drivers, who say it's uncomfortable.