Overview

• FIA activated its heat‑warning protocol at the Singapore GP, compelling teams to install the Driver Cooling System when the 31°C index is reached.
• When the protocol is active in 2025, wearing the cooling vest remains optional, the in‑car unit is mandatory, minimum car weight rises to 805 kg, and non‑wearers must carry an extra 0.5 kg in the cockpit.
• The 2026 regulations are currently written to require vest use in triggered events, though the FIA says it is still evaluating options and continuing discussions with drivers.
• Max Verstappen rejects being compelled to wear the vest, citing discomfort and limited effectiveness after 15–20 minutes, while Lewis Hamilton argues the choice should remain with drivers.
• Opinions are split as George Russell reports the system can be useful from prior tests, Oscar Piastri warns failures can worsen conditions, and the setup combines an in‑car chiller with a hose‑lined fireproof undershirt.