What is the role of engine coolant (liquide de refroidissement) and what should you do if the engine temperature gauge reaches the red zone?

1. It dissipates engine heat; pull over immediately, switch off the engine, and allow it to cool before checking coolant levels (never open a hot radiator cap)
2. It lubricates the gearbox; continue driving at high speed to force air through the engine
3. It fuels the air conditioning; turn the AC on maximum cold to cool the engine
4. It cleans the exhaust; pour cold water over the hot engine block immediately