No federal rule says your employer must install air conditioning, so not having AC at work is not automatically an OSHA violation. But that is only half the answer. Under the General Duty Clause of the Occupational Safety and Health Act, employers must keep the workplace free from recognized hazards likely to cause death or serious physical harm, and excessive heat is a recognized hazard. If the workplace is dangerously hot and the employer has done nothing meaningful to reduce the risk, OSHA can cite the employer whether or not an air conditioner is part of the fix.1Occupational Safety and Health Administration. OSH Act of 1970 – Section 5 Duties
Why There Is No AC Requirement, and Why That Does Not End the Question
OSHA has no regulation setting a maximum indoor temperature or mandating air conditioning. What it has is Section 5(a)(1) of the OSH Act, which requires a workplace “free from recognized hazards that are causing or are likely to cause death or serious physical harm.”1Occupational Safety and Health Administration. OSH Act of 1970 – Section 5 Duties Heat-related illness and death are well-documented workplace hazards, so an employer who ignores dangerous heat is exposed to enforcement even without a specific temperature standard.2Occupational Safety and Health Administration. Heat – Standards
The practical rule is that the employer has to do something feasible about the heat. Air conditioning is one option, not the only one.
What Counts as a Reasonable Response to Heat
OSHA treats air conditioning as one engineering control among several. Increased airflow, de-humidification, reflective shielding against radiant heat sources, and cooled break areas all count as ways to bring heat exposure down.3Occupational Safety and Health Administration. Overview: Working in Outdoor and Indoor Heat Environments Evaporative coolers can lower temperatures by 10 to 20°F when humidity is below 50 percent. Administrative measures also count: rescheduling strenuous work to cooler hours, rotating workers through less heat-intensive tasks, and providing water and rest breaks.4Occupational Safety and Health Administration. Heat Illness Prevention Campaign – Employer Responsibilities
So a warehouse without AC is not, by itself, illegal. A warehouse without AC, without fans, without cooled break space, without water access, and without any heat plan is where the General Duty Clause starts to bite.
When Heat Becomes a Violation
OSHA looks at whether the employer took reasonable steps given the conditions. Inspectors weigh water availability, break schedules, ventilation, training, and whether workers have been taught to recognize signs of heat illness. A useful preview of where the line sits comes from OSHA’s proposed Heat Injury and Illness Prevention standard, published as a Notice of Proposed Rulemaking on August 30, 2024, covering general industry, construction, maritime, and agriculture.5Occupational Safety and Health Administration. Heat Injury and Illness Prevention in Outdoor and Indoor Work Settings Rulemaking The public hearing process concluded in mid-2025, and the rule has not been finalized.
The proposed rule would create two temperature triggers:6OSHA. Heat Injury and Illness Prevention in Outdoor and Indoor Work Settings – NPRM – Reg Text
- At a heat index of 80°F, employers would have to provide drinking water, allow paid rest breaks as needed to prevent overheating, and designate break areas with cooling. Indoor break areas would have to be air-conditioned or have increased air movement.
- At a heat index of 90°F, employers would additionally have to provide a paid 15-minute rest break at least every two hours. Time spent walking to the break area or putting on PPE would not count toward the 15 minutes.
Indoor break areas under the proposed rule would need to be large enough to accommodate all workers on break at the same time, and air-conditioned or ventilated with de-humidification where appropriate.7Occupational Safety and Health Administration. Heat Injury and Illness Prevention in Outdoor and Indoor Work Settings – NPRM Indoor areas that regularly exceed 120°F would require warning signs. Even before this rule is finalized, its thresholds signal where OSHA views heat as a serious hazard.
State Rules That Go Further
Several states with OSHA-approved plans have adopted their own heat-specific standards that impose enforceable requirements beyond federal guidance. California’s heat illness prevention standard triggers employer obligations at 80°F and requires water, shade, and planning.2Occupational Safety and Health Administration. Heat – Standards If you work in a state-plan state, check whether your state has its own heat rule, because the answer to whether your workplace is compliant may depend on state requirements rather than federal ones.
Penalties and How Enforcement Actually Looks
OSHA enforces heat safety mainly through inspections triggered by worker complaints, referrals, or targeted programs. Between 2011 and 2021, at least 436 workers died from environmental heat exposure on the job.8Bureau of Labor Statistics. 36 Work-Related Deaths Due to Environmental Heat Exposure in 2021 As of January 2025, maximum penalties stand at $16,550 per serious violation and $165,514 per willful or repeated violation, with annual inflation adjustments.9U.S. Department of Labor. US Department of Labor Announces Adjusted OSHA Civil Penalty Amounts for 2025
Real cases show how this plays out. In 2013, OSHA cited A.H. Sturgill Roofing, Inc. after a worker died from heat-related illness. The citation alleged the company failed to implement an adequate heat illness prevention program and did not provide adequate training. The case reached the Occupational Safety and Health Review Commission in 2019 and became a significant test of General Duty Clause enforcement for heat exposure.10Occupational Safety and Health Review Commission. Commission Issues Decision in A.H. Sturgill Roofing, Inc. Indoor work is not exempt: OSHA cited United Parcel Service after workers inside trailers and loading areas were exposed to temperatures between 90 and 101°F without adequate ventilation or a heat stress program, faulting the employer for the absence of fans, cooled break areas, and effective heat monitoring.11Occupational Safety and Health Administration. Citation 92835.015/01001
How to File a Complaint About a Hot Workplace
If your workplace is dangerously hot and your employer will not act, you can file a safety complaint with OSHA. Options include the online complaint form, phone at 1-800-321-OSHA (6742), letter by mail or fax, or a visit to a local OSHA office.12Occupational Safety and Health Administration. File a Complaint OSHA keeps the identity of the person filing confidential, so your employer will not be told who raised the concern. Complaints alleging immediate danger to life get priority.
Protection Against Retaliation
Section 11(c) of the OSH Act makes it illegal for an employer to fire, demote, transfer, or otherwise retaliate against you for filing a safety complaint, participating in an inspection, or exercising any other right under the Act.13Whistleblowers.gov. Occupational Safety and Health Act (OSH Act), Section 11(c) If retaliation happens, you have 30 days from the date of the adverse action to file a whistleblower complaint with OSHA. That deadline is strict, and complaints filed later may only be referred to other agencies rather than investigated by OSHA directly.14OSHA. Protection From Retaliation for Engaging in Safety and Health Activity under the OSH Act If you have been punished for raising heat safety concerns, act quickly.