Formula 1 has declared this weekend's Bahrain Grand Prix in Malaysia a heat-hazard race, the third such designation this year following the Austrian and Italian Grands Prix. Temperatures at Malaysia's Sepang circuit are forecast to reach 31-33°C across the race weekend, with high humidity and potential rain each day.
The heat-hazard ruling allows drivers to use an in-car cooling system that flows chilled liquid through pipes in a fireproof vest worn under their overalls. The system must be fitted to the car, but wearing the vest is optional. Drivers who opt out must carry 0.5kg of cockpit ballast.
Some drivers prefer to avoid the cooling system due to discomfort and reliability issues, as the coolant can run out before race finish and reach car temperature levels significantly higher than ambient air. Cockpit temperatures in Formula 1 cars can exceed 40°C, making overheating a serious concern for drivers wearing multiple layers of fireproof clothing.
This weekend's event takes place in Malaysia as an alternative venue for the Bahrain race, which was postponed from its original April date due to Middle East conflict. The Sepang track near Kuala Lumpur has long been known as one of the most physically demanding circuits for drivers due to its equatorial location.