The Federal Heat Rule Slipped to 2027. Heat Disclosure Is Already Due

For most of the past two years, the working assumption inside US safety and sustainability teams was that a national heat standard would arrive, and that heat programs could be built to its specification once it did. That assumption has just been pushed back again. In mid-September OSHA said it has "different thoughts" on its own proposal and wants another round of public input, moving a final rule out to late 2027. It would be easy to read that as more time. The calendar outside Washington says the opposite: heat exposure is already regulated in seven states, already inside European disclosure requirements, and already showing up in the questions investors and customers ask about how a company treats the people doing its hottest work.

The Federal Rule Keeps Moving Right

The proposed Heat Injury and Illness Prevention standard was published in August 2024. According to Environment+Energy Leader, OSHA received more than 43,000 public comments, held virtual hearings through June 2025 and closed post-hearing comments in October 2025. Then, on September 16, 2026, OSHA standards director Andrew Levinson said the agency plans a supplemental proposal "in the coming months," as Perry Weather's tracker of the rulemaking reports. The current Unified Agenda projects that supplemental proposal for December 2026 and final action for October 2027.

The scale of what is being deferred is not small. The proposal would apply to an estimated 36 million workers across general industry, construction, maritime and agriculture, indoors and outdoors. It sets an initial trigger at an 80°F heat index, where employers would have to provide water, rest and shade, and a high-heat trigger at 90°F, where observation and mandatory breaks would step in. Perry Weather notes that more than 33,000 work-related heat injuries and illnesses were recorded between 2011 and 2022, a figure widely regarded as an undercount.

States and Other Jurisdictions Did Not Wait

While the federal timeline slipped, the patchwork filled in. In a September 22 post, the Environmental Defense Fund counts seven states with occupational heat protections: California, Colorado, Maryland, Minnesota, Nevada, Oregon and Washington. Virginia's governor signed SB 288 in April 2026, directing state regulators to write a workplace heat standard, and New York City issued an executive order on worker heat illness prevention in June. EDF puts the human cost plainly: heat is the deadliest weather-related hazard in the country, killing roughly 1,300 people a year.

For a multi-state employer, that means the real compliance question is no longer when the federal rule lands but which of several different state thresholds, plan requirements and recordkeeping rules already apply at each site. The same is true overseas. Environment+Energy Leader notes that Australia updated its Safe Work guidance on heat management at the start of 2026, with new workplace exposure limits arriving in December 2026.

Hong Kong shows what happens where guidance stops short of law. Mongabay reports that the city hit a record 36.9°C on August 9, 2026, and that the number of very hot days has quadrupled since the 2000s. Its heat stress warning system, revised in August, remains advisory, and a survey cited by Mongabay found nearly 40 percent of outdoor workers labored more than four hours without additional rest during heat warnings. "It's just an appeal, encouragement; there's no law," one worker advocate told the outlet.

Why This Is Now a Disclosure Problem

The shift that sustainability teams most often miss is that heat has moved from the EHS manual into the sustainability report. Even after the Omnibus I package narrowed its scope, the EU's Corporate Sustainability Reporting Directive still requires companies with more than 1,000 employees and €450 million in net annual turnover to disclose physical climate risks under ESRS E1, and Environment+Energy Leader points out that heat is a physical climate risk. The standard asks for that analysis at the asset level, across scenarios, with double materiality applied. A paragraph about business continuity does not satisfy it.

Wave one companies, those already reporting under the old Non-Financial Reporting Directive, are disclosing now using 2025 data. That puts the gap in the current reporting cycle. A company whose climate risk section describes heat in general terms, while its safety team holds site-level heat illness records and its suppliers run factories and job sites in hot regions, is producing two stories that do not reconcile. Regulators and investors are increasingly reading both.

The supply chain is where the exposure concentrates. Construction, agriculture, logistics and contract manufacturing carry most of the heat risk, and much of that work sits with suppliers rather than direct employees. A labor-standards program that audits wages and hours but not heat protections leaves out one of the fastest-growing worker welfare risks in the value chain.

The Heat Readiness Playbook

• Plan to the strictest state rule, not the federal draft: Map every US site against the seven state standards and build one program that meets the toughest thresholds, so a final federal rule becomes a gap check rather than a rebuild.
• Write the heat plan down: Name the trigger temperatures, the responsible supervisors and the actions required at each level, and record when those actions are actually taken.
• Map sites against heat hazard data: Replace company-wide climate narrative with a facility-level view of where workers face dangerous heat, which is what ESRS E1 asks for.
• Reconcile EHS records with the sustainability report: Make sure heat illness incidents, recordkeeping and climate risk disclosure tell the same story.
• Extend supplier assessments to heat: Add heat protections, rest breaks and water access to supplier questionnaires and audits in hot regions.
• Treat heat alerts as an operational event: Connect weather warnings to work scheduling and site communication so a heat advisory changes what happens on the ground the same day.