Updated OSHA Heat Illness NEP Targets High-Risk Workplaces
Author: Taylor Lewellyn, Brightmine Legal Editor

Average global temperatures are continuing to trend upward - the last 10 years have been the warmest on record, according to NASA - and both indoor and outdoor workers face increasing risks from heat hazards.
In response, the federal Occupational Safety and Health Administration (OSHA) recently updated the National Emphasis Program (NEP) that protects workers from heat-related hazards by focusing inspections and outreach in industries and workplaces where heat stress risks are most likely to occur.
Originally issued in April 2022, the revised NEP - Outdoor and Indoor Heat-Related Hazards uses OSHA and Bureau of Labor Statistics (BLS) data from calendar years 2022-2025 to direct inspection priorities to 55 high-risk industries in indoor and outdoor work settings. The NEP became effective on April 10, 2026, and will run for five years.
What Is Heat-Related Illness?
Under normal circumstances, the human body relies on its ability to get rid of excess heat, also known as heat dissipation, to maintain a healthy internal body temperature. This process usually happens naturally through sweating and increased blood flow to the skin. However, heat dissipation can be hampered by extreme temperatures or overexertion, which can lead to heat-related illness.
Heat-related illnesses can range from relatively mild conditions (like heat cramps) to more serious illnesses, including heat exhaustion and heat stroke; heat stroke can be deadly.
BLS data indicates that between 2021 and 2024, exposure to environmental heat resulted in an average of 48 fatalities per year, a number that may not reflect the true magnitude of the problem. In addition to being dangerous for employees, on-the-job exposure to extreme temperatures can be disruptive for employers. BLS reports that between 2021 and 2024, exposure to environmental heat resulted in an estimated average of 3,793 days away, restricted and transfer (DART) cases per year.
Three Lists of High-Risk Industries
The NEP includes three lists of industries it considers likely to have heat-related hazards. Here are some of the industries the agency has flagged (see Appendix A of the NEP for the complete lists):
Non-Construction Industries
- Cattle ranching and farming
- Crop production support activities
- Bakeries and tortilla manufacturing
- Sawmills
- Foundries
- Department stores
- Freight trucking
- Local messengers and delivery
- Landscaping and tree services
- Auto repair and maintenance
Construction Industries
- Residential building construction
- Non-residential building construction
- Specialty trade contractors
Other Industries
- Restaurants and other eating places
- Some temp employment agencies
- Telecommunications carriers
(Heat) Waves of Legislation at the State Level
In addition to federal enforcement, numerous states have passed indoor and/or outdoor heat illness prevention standards:
- California enforces the Heat Illness Prevention in Outdoor Places of Employment standard and the Heat Illness Prevention in Indoor Places of Employment standard. Both require employers to take specific actions, including providing water, access to cool-down areas, rest breaks, training and acclimatization when ambient temperatures reach a specified threshold.
- Colorado's Heat Illness and Injury Protection Rules for Agricultural Employers apply on days when the temperature at an agricultural worksite is, or is forecast to be, at least 80 degrees Fahrenheit. In addition, Colorado recently expanded heat protections to employees across all industries by directing Colorado's Division of Labor Standards and Statistics to begin collecting and sharing data concerning temperature-related injury, illness and worksite emergencies by January 15, 2027. The state also directed the Division to develop a model temperature-related injury and illness prevention plan on or before July 1, 2028.
- Maryland has a detailed heat illness prevention standard that applies when employees' work activities, indoor or outdoor, expose them to a heat index that equals or exceeds 80 degrees Fahrenheit.
- Minnesota's heat stress standard protects indoor and outdoor workers by requiring employers to train on the hazards of heat exposure if exposures are expected to approach the limits outlined in the heat stress standard.
- Nevada requires businesses with more than 10 employees to perform a one-time, written job hazard analysis to assess working conditions that may cause occupational exposure to heat illness.
- Oregon's permanent Heat Illness Prevention Rules apply whenever an employee performs work activities in indoor or outdoor environments where the heat index reaches or exceeds 80 F.
- Washington has rules regarding outdoor heat exposure protections that apply to all employers with employees performing work in an outdoor environment when they are exposed to outdoor heat.
- Starting in 2028, Virginia employers will be required to implement heat illness-prevention plans.
Employer Readiness
In addition to staying apprised of the latest heat hazard-related legislation, employers can, at a minimum, take the following steps to safeguard employees' health and safety against extreme heat:
- Provide adequate water, rest breaks and shade or cool rest areas;
- Encourage employees to consume sufficient fluids, both on and off the job;
- Use air conditioning and changes to workloads and schedules when possible;
- Implement an acclimatization process to help workers gradually increase their exposure to hot working conditions;
- Train employees to recognize and prevent heat-related illness and its symptoms and how to respond if they or a fellow employee appears to be suffering from a heat-related illness; and
- Implement a "buddy" system that pairs workers together and makes it easier for co-workers to identify signs of heat illness.
Additionally, OSHA's On-Site Consultation Program, a free and confidential health and safety consulting program for small- and medium-sized businesses, can assist employers with developing strategic approaches for addressing heat-related illnesses and injuries in workplaces.
By taking proactive steps to prevent heat-related illnesses and injuries in the workplace, employers can protect their employees while reducing compliance risks and productivity disruptions.