News and Publications

OSHA Proposes New Heat Injury and Illness Prevention Standard

As summer temperatures shatter records across the country, the Occupational Safety and Health Administration (OSHA) is turning up the heat on employers in an effort to protect workers from high temperatures. In a continuation of OSHA’s ongoing Heat Illness Prevention Campaign, OSHA proposed a new standard on August 30, 2024, to prevent heat injury and illness.

The proposed standard for Heat Injury and Illness Prevention in Outdoor and Indoor Work Settings would replace OSHA’s existing National Emphasis Program on Outdoor and Indoor Heat-Related Hazards. The existing program is based on the General Duty Clause and is in force now. The proposed standard, which could impact as many as 36 million workers nationwide, would impose new duties on employers to safeguard against heat-related hazards and health risks for indoor and outdoor work.

The proposed standard would require employers whose workers might be exposed to high heat conditions to develop and implement a worksite Heat Injury and Illness Prevention Plan (HIIPP). This site-specific plan would include a comprehensive list of the types of work activities covered by the plan, all policies and procedures necessary to comply with the standard’s requirements, emergency response and planning procedures, and an identification of the heat metric the employer will monitor. For monitoring, employers may choose between either the heat index or the wet bulb globe temperature, and they must retain monitoring records for six months. The proposed rule establishes two heat triggers that would require employers to implement increased employee protections:

  • Initial heat trigger: At an 80 degrees F heat index (or a wet bulb globe temperature equal to the NIOSH Recommended Alert Limit), the proposal would require employers to implement measures such as providing (1) a minimum of one quart of water per employee per hour, (2) break areas for employees to cool down, (3) temperature controls such as air conditioning or fans, (4) a chance for acclimatization for new employees and employees returning from more than two weeks away from work; (5) paid rest breaks if needed; and (6) effective communication means with employees.
  • High heat trigger: At a 90 degrees F heat index (or a wet bulb globe temperature equal to the NIOSH Recommended Exposure Limit), the proposed standard would require employers to additionally provide mandatory paid rest breaks, observe for signs and symptoms of heat-related stress, and provide hazard alerts to employees. In addition, the employer would be required to place warning signs in indoor work areas with ambient temperatures above 120 degrees F.

Additionally, employers would be required to train employees on multiple topics, including heat stress hazards, heat-related injuries and illnesses, risk factors for heat-related injury or illness, and the importance of drinking water to prevent heat-related illness or injury. The rule would also require supplemental training for supervisors and annual refresher training for all workers.

The proposed standard would apply to all employers conducting outdoor and indoor work in all general industry, construction, maritime, and agriculture sectors, unless subject to an exception. The exceptions generally apply to work where employees are unlikely to be exposed to extended high heat conditions (such as air-conditioned office work) or emergency response work (such as firefighting).

The proposed standard would affect industries nationwide, but the impact will be the largest for employers in hotter local climates.

Without a federal heat standard, five states with OSHA-approved State Plans have adopted their own heat standards (California, Colorado, Minnesota, Oregon, and Washington), and one additional state (Maryland) has published a proposed standard. Once OSHA finalizes a heat standard, all states with OSHA-approved State Plans (including those that already have heat standards in place) would be required to adopt a standard that is identical to or “at least as effective” as the federal rule, unless they can demonstrate that their existing standards are already “at least as effective” in protecting workers. Therefore, both employers subject to Federal OSHA and in State Plan states should pay close attention as OSHA proceeds with its rulemaking process.

The comment period for OSHA’s proposed rule closes on December 30, 2024.

Beveridge & Diamond’s Occupational Safety & Health practice group works alongside clients’ legal, EHS, and technical teams to help resolve critical enforcement, compliance, and regulatory issues relating to their facilities and operations. For more information, please contact the authors.


The wet bulb globe temperature is an environmental temperature determined by measuring dry air temperature, humidity, and radiant energy – such as sunlight being absorbed by clothing – to calculate the thermal load on an individual. National Institute for Occupational Safety and Health (NIOSH), Criteria for a Recommended Standard on Occupational Exposure to Heat and Hot Environments, xxiii, 113-14 (2016) (available at https://www.cdc.gov/niosh/docs/2016-106/default.html).