Hard hats are designed to:

Hard hats are primarily designed to provide protection against various types of hazards encountered in the workplace, including electrical shocks and burns. They are made from materials that can insulate the wearer from electrical currents, which is crucial in environments where there is the possibility of exposed electrical sources. This protection is vital for preventing serious injuries or fatalities resulting from electrical accidents.

In addition to electrical protection, hard hats also offer defense against impact from falling objects. They are constructed to withstand impacts from objects that might fall on the head in a construction or industrial setting. The design of hard hats incorporates a suspension system that helps absorb shock and distribute the force of an impact, protecting the head and preventing injury beyond just electrical hazards.

The other options do not encompass the full range of protection that hard hats provide. Some options limit the type of protection to specific situations or types of objects, which underscores why they don't correctly represent the comprehensive safety function of hard hats.