What is the main function of safety equipment such as fire extinguishers in trucks?

The main function of safety equipment such as fire extinguishers in trucks is to help manage emergencies. Fire extinguishers are specifically designed to provide a quick response to unexpected fires, which can occur in a variety of situations, particularly in vehicles that may carry flammable materials or be involved in accidents. Having a fire extinguisher readily accessible allows drivers or passengers to act swiftly to suppress a small fire before it escalates into a larger, more dangerous situation. This proactive measure is crucial for ensuring safety on the road.

The other options do not align with the primary purpose of fire extinguishers. While improving vehicle performance, storing emergency supplies, and maintaining optimal temperature may be important in their contexts, they are not the intended use of fire extinguishers, which are fundamentally about managing fire-related emergencies.