What does it mean when the car's coolant light comes on?

[JuliaDella]

The reasons for the car's coolant light coming on include insufficient coolant, excessively high engine temperature, cooling fan malfunction or failure, and damaged thermostat. Here are some additional relevant information: 1. Note: When the coolant temperature warning light comes on, you should stop the car for inspection, but do not turn off the engine. Park the vehicle in a safe area and let the engine continue running at idle speed. Open the hood to allow heat dissipation. If you see steam coming from the hood, observe first and do not open it hastily to avoid burns. 2. Check the coolant reservoir: After parking, first check if the coolant level in the auxiliary reservoir is too low. Open the engine hood and see if the coolant level in the auxiliary reservoir is normal. If the coolant level is below the minimum line, it indicates that the coolant is insufficient. If possible, add coolant. If coolant is not available, you can temporarily use mineral water as a substitute, but remember to replace it with new coolant afterward.