Which of the following is a risk associated with overheating in electrical devices?

Overheating in electrical devices leads to a significant risk known as reduced electrical efficiency. When a device becomes too warm, the materials and components within it can start to fail or operate less effectively, which leads to increased resistance and energy loss. This inefficiency manifests as wasted energy, often resulting in higher operational costs and the potential for further damage to the device. Overheating is often tied to inadequate cooling, poor ventilation, or excessive load, all of which can negatively impact the performance and reliability of the device.

The other options do not accurately reflect the consequences of overheating. Increased signal strength is not associated with overheating; rather, heat can cause signal degradation. Lower operational costs would not result from overheating, as increased energy consumption and potential damage typically drive costs up. Lastly, improved device lifespan is contradicted by overheating, which is known to reduce the longevity of electronic components due to stress and degradation that excess heat causes.