WASHINGTON — The Biden administration proposed a new rule Tuesday to address excessive heat in the workplace, as tens of millions of people in the U.S. are under heat advisories due to blistering temperatures.

If finalized, the measure would protect an estimated 36 million U.S. workers from injuries related to heat exposure on the job — establishing the first major federal safety standard of its kind. Those affected by excessive heat in the workplace include farmworkers, delivery and construction workers, landscapers, and indoor workers in warehouses, factories and kitchens.

Despite increased awareness of the risks posed to human health by high temperatures, extreme heat protections — for those routinely exposed to heat index readings above 80 degrees — have lagged.

Under the proposed rule, employers would be required to identify heat hazards, develop emergency response plans related to heat illness, and provide training to employees and supervisors on the signs and symptoms of such illnesses. They would also have to establish rest breaks, provide shade and water, and heat acclimatization — or the building of tolerance to higher temperatures — for new workers.

Penalties for heat-related violations in workplaces would increase significantly, in line with what workplaces are issued for violations of Occupational Safety and Health Administration rules, a senior White House administration official said.

About 2,300 people in the U.S. died from heat-related illness in 2023. Workers with prolonged exposure to extreme heat are among the most vulnerable to related health risks, such as heatstroke and other illnesses, according to the Centers for Disease Control and Prevention.

Over the past year, Florida and Texas — led by Republican Govs. Ron DeSantis and Greg Abbott, respectively — passed legislation preventing local governments from requiring heat protections for outdoor workers.

If finalized, the Biden administration’s rule would override state measures.