This chapter applies to an employer with employees whose employment activities, indoor or outdoor, expose employees to a heat index in the area where the employee is working that equals or exceeds 80 degrees Fahrenheit. This chapter does not apply to: Emergency operations and essential services as defined in Regulation .03B(4) of this chapter that involve protecting life or property; Incidental exposures when an employee is not required to perform work activities for more than 15 consecutive minutes per hour; or Buildings, structures, and vehicles that have a mechanical ventilation system or fan that maintains the heat index below 80 degrees.