Heat safety at work: updates on OSHA's proposed rule and state laws

In recent years, extreme heat has been recognized as a pressing occupational hazard, prompting significant legislative and regulatory developments to safeguard workers. Both federal and state authorities have introduced new laws and proposals, but there's little consensus on what constitutes a reasonable standard. Here's a look at where we are today:

Federal: OSHA's proposed heat standard

After much uncertainty regarding the future of OSHA's pending heat standard, the Department of Labor announced that it will host a virtual public hearing on the Notice of Proposed Rulemaking (NPRM) on the proposed standard, Heat Injury and Illness Prevention in Outdoor and Indoor Work Settings, on June 16, 9:30 a.m., EDT. The hearing will "continue on subsequent weekdays, if necessary," according to the announcement. Registration isn't required to view the hearing, and instructions for watching will be posted on OSHA's rulemaking webpage.

The public comment period for the NPRM closed on January 14. While a public hearing is the last major step in the rulemaking process, it does not mean the rule will proceed. There are several possible outcomes - adopted as is, significantly altered, or withdrawn.

If enacted, it would be the first nationwide heat regulation and apply to all employers under OSHA's jurisdiction in general industry, construction, maritime, and agriculture sectors, with limited exceptions. It mandates the implementation of a workplace-specific heat injury and illness prevention plan, including assessing heat hazards, instituting engineering and work practice controls based on heat severity, developing emergency response procedures, recordkeeping, and training employees and supervisors.

The standard introduces two key trigger levels for action. The "initial heat trigger" is 80 degrees Fahrenheit. Employers would have to provide accessible, cool drinking water (at least one quart per hour), ensure rest breaks and shaded or air-conditioned areas, frequently monitor the temperature, and establish effective two-way communication with remote employees. The "high heat trigger," when temperatures reach 90°F, requires mandatory paid 15-minute breaks every two hours, buddy systems or supervision monitoring to ensure early detection of heat-related symptoms, and heat hazard alerts to employees about the importance of staying hydrated, taking breaks, how to seek emergency help, and the location of water and break areas. Acclimatization plans for new or returning workers are required under both triggers. View the proposed standard.

Several business groups have actively opposed the proposed standard, citing concerns about costs, operation disruption, and lack of flexibility. Industry representatives argue that the proposed standard's "one-size-fits-all" requirements fail to account for the diverse conditions across various sectors and regions. They advocate for guidelines that allow employers to tailor heat illness prevention programs to their specific circumstances. The U.S. Chamber of Commerce criticizes the prescriptive nature of the proposed rule, suggesting it could lead to OSHA micromanaging employer operations. They recommend a performance-oriented approach that provides flexibility, allowing employers to develop heat illness prevention programs suited to their work environments and employees. Others oppose including indoor heat and object to the acclimation requirements.

Conn Maciel Carey LLP, a labor and employment law firm, agrees that the proposed rule is deeply flawed and examined the pros and cons of pushing OSHA to revise the rule now and produce a heat standard that is flexible, performance-based, and acceptable to the business community.

Pros:

• Absence of a rule leads to a patchwork of state rules and laws that layer burdensome and often conflicting requirements on national employers. State OSHA Plans are already adopting rules and state legislatures in federal OSHA states are actively considering rules.
• If the rule is put on the backburner, it's likely that the deeply flawed rule would be promulgated when there is a change in administration.

Cons:

• A final rule could lead to more citations. OSHA now relies on its General Duty Clause ("GDC") for enforcing heat illness hazards, and typically, it is tougher to enforce under the GDC than it is under a specific standard. However, if the compliance requirements are more reasonable, there will be far fewer citations than under the one currently proposed.
• There are always costs associated with compliance with a new standard. But the promulgation of a heat illness prevention standard is likely not a question of "if," but rather "when." The costs associated with compliance would be less burdensome under a carefully revised rule than under the rule as currently proposed.

It's important to remember in the absence of a rule, OSHA's Heat National Emphasis Program ("NEP") remains in effect until April 8, 2026, and citations can be issued under the General Duty Clause.

State rules

California (State Plan)
California has long been at the forefront of occupational heat safety. It adopted its first outdoor heat illness prevention standard in 2005. A new indoor heat standard was adopted on June 20, 2024, and went into effect on July 23, 2024.

Colorado (Federal OSHA)
Colorado's heat regulation, which applies only to agriculture, was adopted on January 31, 2022, and became effective on May 1, 2022.

Connecticut (Federal OSHA)
Senate Bill 830 proposes new rules based on California safety standards, covering everything from shade areas to drinking water temperature.

Florida (Federal OSHA)
In April 2024, Florida enacted HB 433, a law prohibiting local governments from implementing worker heat-exposure protections.

Illinois (Federal OSHA for private employers)
A bill, "Workplace Extreme Temperature Safety Act," was introduced in the General Assembly in February 2025. This bill aims to establish excessive heat and cold standards, requiring the state's Director of Labor to adopt rules by January 1, 2026.

Maryland (State Plan)
Maryland adopted its heat stress regulation on September 30, 2024. It applies to both outdoor and indoor workplaces.

Minnesota (State Plan)
Minnesota adopted an indoor workplace heat standard in 1997 and an outdoor standard on July 1, 2024.

Nevada (State Plan)
Nevada's heat illness prevention regulation was adopted on November 15, 2024, and enforcement began on April 29, 2025, 90 days after the publication of guidance on January 29, 2025. It covers both outdoor and indoor workplaces in specific industries.

New Mexico (State Plan)
On March 13, 2025, NMOSHA proposed a rule requiring employers to implement safety protocols such as acclimatization periods, access to cool drinking water, shaded rest breaks, and training on heat illness prevention.

Oregon (State Plan)
Oregon adopted an emergency heat illness prevention rule on July 8, 2021, which was made permanent on June 15, 2022. It covers both outdoor and indoor workplaces.

Vermont (State Plan)
Lawmakers are considering a bill, S.B. 153, that would regulate worker exposure to extreme temperatures and require employers to develop and implement a protection plan.

Washington (State Plan)
Washington initially adopted its Outdoor Heat Exposure rule in July 2008. However, this rule was limited to certain industries during specific periods of the year. In response to a 2021 heat wave, the state adopted broader, emergency rules in July 2021. These emergency rules were then codified into permanent regulations in June 2023, which took effect on July 17, 2023, and are now year-round, applying to all employers with outdoor workers.

The regulations vary significantly by state with differing temperature thresholds for triggering heat safety protocols and preventive requirements as well as varying coverage of worker groups. If there were a federal standard, there would be more uniformity. The State Plan states must adopt standards that are at least as protective of workers as the federal regulations. Many states adopt the federal standards verbatim, but others may have more stringent requirements or address unique local hazards. In states that are covered by Federal OSHA, OSHA standards preempt state laws.

Employers should abide by existing standards and stay informed about evolving regulations. In states without specific heat safety regulations, employers should proactively implement measures that are appropriate for their operations to protect workers from heat-related injuries and illnesses.