President Joe Biden on Tuesday proposed a new rule to address excessive heat in the workplace, warning — as tens of millions of people in the U.S. are under heat advisories — that high temperatures are the country's leading weather-related killer.

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.

Biden highlighted the proposed rule as one of five steps his Democratic administration is taking to address extreme weather as Hurricane Beryl is already ripping through the Caribbean in an ominous sign for the summer.

Biden used his remarks at the D.C. Emergency Operations Center to blast those Republican lawmakers who deny the existence of climate change, saying, “It's not only outrageous, it's really stupid.” Biden noted that there are human and financial costs from climate change, saying that weather-inflicted damage last year cost the economy $90 billion.

“More people die from extreme heat than floods, hurricanes and tornadoes combined,” Biden said. “These climate fueled extreme weather events don’t just affect people’s lives. They also cost money. They hurt the economy, and they have a significant negative psychological effect on people.”

The Democratic president, who's seeking reelection in part on his environmental record, said that the Federal Emergency Management Agency was also finalizing a rule to factor in possible flooding risks for federal construction projects.

In addition, FEMA was announcing $1 billion in grants to help communities deal with natural disasters, while the Environmental Protection Agency was releasing a new report on climate change's impacts. Lastly, Biden said his administration would hold a conference titled “White House Summit on Extreme Heat” in the coming months.

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 Fahrenheit (27 degrees Celsius) — have lagged.

“The purpose of this rule is simple,” a senior White House administration official told reporters. “It is to significantly reduce the number of worker-related deaths, injuries, and illnesses suffered by workers who are exposed to excessive heat ... while simply doing their jobs.”

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.

An estimated 2,300 people in the U.S. died from heat-related illness in 2023. From 1992 to 2022, a total of 986 workers across all industry sectors in the U.S. died from exposure to heat, with construction accounting for about 34% of all occupational heat-related deaths, according to the Environmental Protection Agency. During that time, 334 construction workers died due to heat exposure on the job.

As the hottest month of the year gets underway, millions of Americans will be at greater risk of heat strokes, dangerous dehydration and heat-related heart stress.

The Labor Department has been developing a standard for how workplaces deal with heat since 2021. Last year, OSHA held meetings to hear about how the proposed measures could affect small businesses.

The AFL-CIO union federation praised the measure. “If finalized, this new rule would address some of the most basic needs for workers’ health and safety,” said AFL-CIO President Liz Shuler.

Heat protection laws in the U.S. have faced steady industry opposition, including from chambers of commerce and other business associations. Many say a blanket mandate would be difficult to implement across such a wide range of industries.

California, Colorado, Oregon, Minnesota and Washington are the only states with workplace standards for heat exposure. Over the past year, Florida and Texas, led by Gov. Ron DeSantis and Gov. Greg Abbott, both Republicans, passed legislation preventing local governments from requiring heat protections for outdoor workers.

If finalized, the Biden administration's rule would override state standards, and states with existing procedures to deal with heat would have to institute measures at least as stringent as the finalized federal rule.

The OSHA plan was announced as the EPA released a new report on climate change indicators in the U.S. The report, last updated in 2016, highlights data showing the continuing and far-reaching impacts of climate change in the U.S. This year’s report adds heat-related workplace deaths and marine heat waves as climate change indicators.

The report lists 57 indicators related to either the causes or effects of climate change.