Though it has never released a heat standard, the Occupational Safety and Health Administration (OSHA) relies on the OSH Act's General Duty Clause to carry out heat-related inspections to insure that employers are providing plenty of water, rest and shade for affected workers during heat waves and other extremely hot periods.

OSHA recently instructed its field inspectors "to expedite heat-related inspections and to issue citations, where appropriate, as soon as possible" during days deemed at or above the weather "danger zone" in a particular area, as determined by advisories from the National Oceanic and Atmospheric Association (NOAA).

A memorandum urging stepped-up enforcement issued in July urges inspectors to use the General Duty Clause to cite employers who have "not taken protective action" even when aware of the risk from heat exposure. The memorandum also instructs inspectors to issue heat-related citations immediately, while other citations observed during the same visit may be postponed for later submission.