OSHA’s Heat NEP, in effect since April 8, 2022, formally expired April 8, 2026. That ended the targeted inspection framework that had driven federal attention toward extreme heat, high air temperatures, high heat index days, and outdoor workers in hot environments.
Here is the plain-English status: the proposed federal Heat Injury and Illness Prevention in Outdoor and Indoor Work Settings rule was published August 30, 2024; the post-hearing comment period closed October 30, 2025; as of May 2026, there is no target date for finalization. With no specific federal heat stress standard in force, OSHA can still cite contractors under the OSH Act General Duty Clause, Section 5(a)(1), for recognized heat illness hazards. OSHA also notes that employers may face citations under related standards, while state-specific standards apply in California, Washington, and Minnesota. Some states, such as California, Washington, and Oregon, have specific heat standards for outdoor workers, while federal OSHA has proposed a national heat standard.
North Carolina operates a state OSHA plan, and South Carolina operates its own. Neither state has adopted a dedicated heat illness prevention rule for construction workers as of the 2026 summer season. In practice, there may be fewer NEP-triggered programmed inspections, but OSHA’s authority is not reduced when heat exhaustion, heat stroke, or another heat-related illness occurs on a jobsite.
| Date | Milestone |
|---|---|
| April 8, 2022 | OSHA Heat NEP began |
| August 30, 2024 | Federal heat rule proposed |
| October 30, 2025 | Post-hearing comment period closed |
| April 8, 2026 | Heat NEP expired |
| May 2026 | No final federal rule target date |
For executives, safety directors, and field supervisors, the enforcement climate has changed, not the risk. High-heat-index afternoons in Charlotte, humid work in Raleigh-Durham, concrete-intensive data center builds along I-85, and coastal Carolina heat waves mean that construction sites combine environmental, operational, and physical hazards that significantly increase the risk of heat illness across construction safety and wellness programs.
Heat stress occurs when the body’s cooling mechanisms fail, causing a rise in core temperature, particularly dangerous for construction workers. Heat stress is also the net heat load on the body resulting from physical activity, environmental factors, and thermal trapping of clothing.
The data is blunt. Construction workers are 13 times more likely to die of a heat-related illness than workers in other industries. Between 1992 and 2016, 285 construction workers died from heat-related causes, which accounted for more than a third of all U.S. occupational deaths from heat exposure. Almost half of all occupational heat fatalities occur on a worker’s first day, with over 70% happening within their first week.
Risk summary: a heat fatality can drive OSHA scrutiny, insurance costs, project delays, civil litigation, and reputation damage. Heat stress can result in significant accidents and injuries due to impaired cognitive function and motor skills. Unmanaged heat stress deteriorates brain function and coordination, raising accident rates on construction sites.
Heat stress in construction is a triple threat: environmental heat, metabolic heat from physical labor, and restricted cooling caused by heavy personal protective equipment. Construction workers face a “triple threat” of environmental heat, metabolic heat from physical labor, and limited cooling due to heavy PPE.
The heat index combines air temperature and humidity into a “feels like” number. A 92°F day in Raleigh with heavy humidity can be more dangerous than a dry 98°F day elsewhere because sweat evaporation slows, the body’s response weakens, and body temperature rises.
Wet bulb globe temperature, or WBGT, goes further by accounting for radiant heat, direct sunlight, wind, humidity, air movement, and air flow. Larger construction projects such as data centers, distribution hubs, and multi-story builds should consider WBGT meters, especially where radiant heat from concrete, steel, roofing, or asphalt compounds the load.
NIOSH guidance and the OSHA-NIOSH Heat Safety Tool help translate heat index readings into action. Once the heat index climbs above roughly 90°F, contractors should increase the frequency of breaks, provide shade, offer cool water, and monitor workers. When the national weather service issues heat advisories, field leaders should treat the day as a heat safety trigger, not a weather note.
Every ABC Carolinas member working outdoors in summer should have a written, job-site-specific heat safety plan updated before June 2026. Preventing heat stress requires a structured approach centered on hydration, rest, and shade, supported by expert construction safety training that reinforces OSHA guidelines.
The plan should be included in the company safety manual and site-specific safety plans, not in a seasonal email that disappears by July.
A mid-sized general contractor building a warehouse in Greenville can make this practical: pre-season planning in April, supervisor training in May, and formal rollout with crews by early June. That written heat illness prevention program becomes both a compliance roadmap and evidence if OSHA, insurers, or plaintiff’s counsel later asks what was done to protect workers.
Acclimatization matters because new workers, returning workers, and workers returning after time away are at elevated risk of heat cramps, heat exhaustion, and other heat-related illnesses. A lack of acclimatization can exacerbate heat stress risks, as the body requires 7 to 14 days to build tolerance to high temperatures.
NIOSH recommends the following step-by-step acclimatization ramp-up protocol:
For example, a new concrete finisher on a July data center slab pour near Concord should not be assigned full exposure on day one. Track exposure status on crew rosters, daily reports, or foreman notes. Documented heat-tolerance planning demonstrates recognized best practice.
Hydration and rest breaks are the frontline defense against the humid Carolinas’ hot weather. Construction workers sweat between 27 oz. and 47 oz. per hour during strenuous work, making it essential to drink more fluids than they think they need to prevent dehydration.
For a roofing crew in Wilmington under a 100°F-plus heat index, start earlier, cluster heavier work in the morning to better manage the physical demands of strenuous tasks, use pop up tents or shaded cooling areas, and reduce afternoon workload. Employers should adjust the starting time for construction work to avoid the hottest parts of the day, allowing workers to perform strenuous tasks during cooler morning hours.
Supervisor training is non-negotiable because OSHA will ask what the foremen knew and did when heat-related symptoms appeared. Heat-related illnesses include heat stroke, heat exhaustion, heat cramps, and heat rash, which can progress rapidly if left untreated. Heat stress can lead to a range of physical illnesses, from discomfort to life-threatening conditions such as heat stroke and heat exhaustion.
Signs and symptoms of heat-related illnesses:
If heat stroke is suspected:
Heat stroke can cause permanent disability or death if response is delayed.
A buddy system is valuable because roofing, masonry, ironwork, formwork, paving, and confined-space work often happen in small teams. Pair workers so each person checks the other for confusion, pale skin, stumbling, irritability, or unusual fatigue.
The buddy system complements supervisor oversight in noisy, visually complex job site conditions. Include it in the written heat illness prevention plan and mention it during pre-task planning when extreme, intense, or high heat index conditions are forecast.
The hierarchy of controls still applies.
Engineering controls may include:
They should also account for radiant heat from concrete, steel, roofing, or asphalt, along with other job-specific heat sources such as welding equipment or roofing kettles where relevant. Designated cooling areas and access to cooling aids, such as wet towels or immersion tubs, are critical for preventing heat stress.
Administrative controls include:
The risk of occupational injury increases by 17.4% during heat waves, which can significantly affect construction worker productivity and safety.
PPE planning matters: Lightweight outer clothing, breathable protective clothing, hard-hat shades, cooling gear, and cooling vests can reduce heat stress, but respirators, arc-flash gear, rain suits, and other personal protective equipment can increase heat strain. The ANSI/ASSP A10.50-2024 Standard for Heat Stress Management in Construction and Demolition Operations outlines industry best practices for managing heat stress, although it is voluntary guidance.
North Carolina and South Carolina do not mandate specific heat-illness prevention standards, but contractors can strengthen their legal and operational position by borrowing structures from California and Washington programs.
The useful pieces are simple: trigger temperatures or heat index thresholds, access to cool drinking water, mandatory shade, cool-down breaks, written procedures, supervisor training, and emergency response. Voluntarily adopting these structures does not import another state’s legal obligations into the Carolinas. It does, however, create evidence that the contractor used recognized heat safety practices.
A Carolinas contractor might set a trigger at a 90°F heat index for added monitoring, mandatory shade access, and more frequent breaks, then escalate again when WBGT or local conditions show added risk from direct sunlight, radiant heat, or limited air movement.
ABC Carolinas STEP, the Safety Training Evaluation Process, is the natural place to embed heat illness prevention into broader safety and management education efforts. Use STEP to track acclimatization rosters, training completion, heat index logs, incident trends, engineering controls, and corrective actions.
Leading indicators matter. Reports of heat rash, heat cramps, and early heat exhaustion may reveal a program gap before a severe event. A member company can compare summer 2024–2025 heat incidents with summer 2026 across Charlotte, Raleigh-Durham, Greenville-Spartanburg, and coastal markets, then adjust schedules, hydration placement, and supervisor training.
ABC Carolinas can help members build templates, toolbox talks, and training outlines aligned with STEP and strong safety culture expectations. Safety directors should review 2025 STEP submissions now and identify areas where heat stress controls and documentation quality can be improved before peak summer.
A single heat stroke fatality in the Carolinas can trigger state OSHA investigations, federal attention, civil lawsuits, project disruption, and reputation damage. The expiration of the Heat NEP may create a false sense of security, but General Duty Clause authority and civil liability exposure remain.
Juries and regulators increasingly view heat incidents as preventable when hydration, shade, rest breaks, acclimatization, and training are missing or poorly documented. Consider two similar events: one contractor has heat index logs, training sign-ins, break schedules, and emergency plan drills; another has no records. The first may defend reasonableness. The second may face willful allegations and larger claims.
For ABC Carolinas members, chapter membership is a platform to strengthen documentation practices. Documentation is not paperwork for its own sake; it is evidence that leaders took reasonable steps to prevent heat-related illnesses, protect workers, and preserve contracts, reputation, and profitability.
The lapse of OSHA’s Heat NEP and the stalled federal heat rule do not reduce contractor responsibility for protecting construction workers from heat illness in the Carolinas. Extreme heat, high heat index conditions, and punishing WBGT readings will still affect work across Charlotte, the Triangle, Upstate South Carolina, the I-85 industrial corridor, and the coastal Carolinas.
Documented acclimatization, hydration, rest breaks, supervisor recognition training, buddy systems, engineering controls, and emergency plan execution form the backbone of a defensible program. Contractors who let documentation lapse because the NEP expired are taking on legal and human risks they do not have to take. Summer 2026 is the wrong moment to assume federal silence equals federal tolerance.
ABC Carolinas executives and safety leaders should review current controls, align them with OSHA heat guidance, NIOSH recommendations, and consensus best practices, and leverage events such as the ABC Carolinas Safety & Health Summit alongside STEP to help every crew return home safely.
Prime contractors should require subcontractors to follow the host site’s heat illness prevention plan and document that requirement in contracts, preconstruction meetings, and weekly coordination meetings. Share heat index thresholds, hydration rules, rest break schedules, and emergency procedures with every subcontractor supervisor, and use chapter safety and health events to reinforce these expectations.
The plan should identify who calls 911, who directs EMS to the scene, and who begins cooling. Stop work, move the worker to shade or a cooler area, remove excess PPE, begin active cooling with water, wet cloths, fans, or immersion if available, and monitor the worker until emergency medical services arrive.
Start with a written template from ABC Carolinas, OSHA, NIOSH, or consensus guidance, then tailor it to the work. Assign one responsible person to monitor heat index data, lead toolbox talks, track acclimatization, and verify access to water, shade, and breaks at each job site, drawing on ABC Carolinas safety and management resources as needed.
A general policy is not enough for higher-risk work. Use roster checkboxes, foreman notes, or hard-hat identifiers to flag workers during their first 7–14 days of exposure to hot weather. Individual tracking is stronger evidence that the company actively managed acclimatization.
Heavy or impermeable PPE increases heat strain by trapping heat on the body and limiting cooling, altering the body’s response to heat. Adjust thresholds downward and schedule high-PPE tasks during cooler periods when possible. For arc-flash gear, respirators, rain suits, or chemical protection, use more conservative work/rest cycles and consider input from industrial hygiene.
