Which of these statements about engine overheating is true?

When dealing with an overheating engine, it is crucial to allow the system to cool down before attempting to remove the radiator cap. This is because removing the radiator cap on a hot engine can result in coolant spraying out under pressure, which can cause serious burns or injuries. The coolant expands when heated and can explode out at high temperatures, posing a risk to anyone nearby. Ensuring that the system has cooled down significantly minimizes this danger, allowing for a much safer process of checking coolant levels or making repairs.

Maintaining proper coolant levels is also vital for engine health, as it ensures the engine operates within an appropriate temperature range. However, the importance of cooling the system before attempting to open the radiator cap takes precedence due to safety concerns.