Car headlights needs heat resistance mainly for the following reasons:

1. High temperature environment: car headlights will be affected by high temperature from vehicle engines and other parts during work. Especially when driving for a long time or at high speed, the surface of lamps will be affected by high temperature. Therefore, car headlights needs to have certain heat resistance, which can work normally in high temperature environment without being deformed or damaged by heat.

2. Lighting effect: The lighting effect in car headlights directly affects driving safety. If the lamp loses its heat resistance in high temperature environment, it may lead to the deformation or damage of the lamp, which will further affect the lighting effect and reduce the visibility and driving safety of the driver.

3. Long-term use: car headlights usually needs to be used continuously for a long time, especially at night or under bad weather conditions. If the lamp lacks heat resistance, it may be deformed or damaged by heat due to long-term work, which will affect the life and stability of the lamp.

4. Safety performance: car headlights is an important lighting equipment for vehicles, and its normal operation is very important for driving safety. If the lamp lacks heat resistance, it may cause circuit failure, bulb short circuit and other problems due to high temperature, which will affect the normal work of the lamp and even cause safety hazards.

To sum up, car headlights needs heat resistance to ensure that it can work normally in high temperature environment and maintain good lighting effect, stability and safety. Only with good heat resistance can car headlights work stably and reliably under various working conditions and improve driving safety and comfort.