What must a driver be cautious of regarding brake heat?

A driver must be cautious of brake heat because excessive heat can lead to brake failures. When brakes are engaged, they convert kinetic energy into heat. If the brakes are used continuously or too aggressively, they can overheat, causing a reduction in braking efficiency, known as brake fade. This occurs when the braking components become too hot to function properly, resulting in a longer stopping distance, less responsive braking, and an increased risk of brake system failure.

Understanding the effects of brake heat is crucial for drivers, especially in scenarios like downhill driving or towing heavy loads where brakes work harder. Properly managing brake usage and allowing them to cool down when necessary helps maintain their effectiveness and ensures safety on the road.

Regarding the other options, while it's true that certain conditions can improve traction and modern brakes have better designs to withstand heat, it's important to remember that heat remains a significant concern for any braking system.