Overheating is the single most common cause of irreparable engine damage. The Temperature Warning Light—usually a red thermometer icon or the words "TEMP" or "OVERHEATING"—is your car’s way of sounding a desperate alarm. Most vehicles use a liquid cooling system where a mixture of water and antifreeze (coolant) circulates through the engine block to absorb heat and then releases it through the radiator. In South Africa’s intense heat, especially during a stop-start commute on the M1 or N1, a failure in this system can cause an engine to "seize" or melt its internal components in a matter of minutes.
If this light illuminates while you are driving, you must act immediately to save your engine: Pull Over: Safely move to the shoulder as soon as possible and turn off the engine. The "Heater Trick": If you cannot pull over immediately, turn your cabin heater to the maximum heat and fan speed. This acts as a secondary radiator, drawing some heat away from the engine and into the cabin (it will be uncomfortable for you, but it might save the engine). Do NOT Open the Cap: Never attempt to open the radiator or coolant reservoir cap while the engine is hot. The system is under high pressure, and opening it can cause a "geyser" of boiling liquid, resulting in severe third-degree burns.