one safety coordinator dude trying to make people put on their hardhat.

First: He reported that whenever he came across workers not wearing hard hats, he would tell them with a lot of authority of the regulation and that they must comply.
Result:They puted it on, and after he left, they removed the hats.

Experiment: The next time he found some of the workers not wearing their hard hat, he asked if the hats were uncomfortable or did not fit properly. Then he reminded the men that the hat was designed to protect them and suggested that it always be worn on the job.

Result: increased compliance with no resentment or emotional upset.