Overview
- The debate intensified Saturday at the Singapore Grand Prix when the FIA declared a heat hazard that requires teams to fit cooling hardware while leaving drivers free to wear or skip the vest.
- Drivers are sharply divided: George Russell favors wide use and eventual mandates, Max Verstappen rejects the vests for comfort and limited run time, and Isack Hadjar has called for a full ban.
- Teams report real technical limits where the chilled fluid can warm after about 20–40 minutes or 15–20 laps, and a pump failure in Austin circulated roughly 50°C water through Kimi Antonelli’s vest, causing heat illness.
- The FIA rule ties mandatory car installation to a heat‑index threshold above 31.0°C but makes wearing optional with a 0.5kg cockpit ballast for those who opt out, creating uneven uptake across the grid.
- Although vest hardware is formally outside the budget cap, teams say designing reliable, compact systems still diverts engineering time and forces a choice between cooling work and other car upgrades, which raises the prospect of a shared or mandated solution.