A Complete Guide to OSHA and Heat Stress in the Workplace

Heat stress is a constant threat to workers in many industries, to the extent that OSHA has regulations in place to ensure heat safety in the workplace. Specifically, OSHA’s General Duty clause requires employers to ensure their employees are safe from all identifiable hazards at the work site.

Prioritizing heat safety is also the right thing to do, as heat illness can result in long-term, even fatal effects on workers. Many researchers assert that official data doesn’t capture how many workers die every year due to heat stress on the job, but some data available confirms that dozens of workers suffer fatal heat illnesses every year.

This guide is for employers looking to improve workplace safety and ensure they are in compliance with OSHA regulations.

Risk Factors for Heat Stress

Heat stress leads to heat illness, so minimizing its impact on workers is paramount. That starts with identifying heat stress risk factors, which include:

  • Heat hazardsThe most obvious risk factor is the presence of heat-generating sources, like ovens, furnaces and areas where industrial machinery is outputting a lot of thermal energy into the environment (assembly lines are one example).
    Outdoor work typically means one difficult-to-avoid heat hazard: the sun. Duration of sun exposure is an essential data point to track in this case.
  • Work intensity – In workplaces where moderate to intense activity is required, exertion will increase the risk of heat illness. Extended periods of work in hazardous conditions will also increase the chances of experiencing heat illness.
  • Protective wear – Personal protective equipment (PPE) protects against environmental hazards but doesn’t ventilate well and will therefore trap a lot of heat.
  • Certain health conditions and medications – People with certain health conditions, like cardiovascular problems, are at a higher risk of developing heat illness and more likely to experience severe symptoms.

Symptoms of Heat Related Illness

Heat illness may emerge gradually or suddenly. In most cases, there is a brief period of time during which symptoms are present and others have time to respond and help. Recognizing the symptoms of heat illness is critical for a proper emergency response then. Here’s what to look for:

  • Confusion or irritability
  • Loss of balance (ataxia) or weakness
  • Excessive sweating or a complete lack of it
  • Skin that’s clammy or pale
  • Muscle cramps
  • Nausea and vomiting
  • A weak pulse
  • Loss of consciousness

If any of the above signs are present, the worker should be removed from hazardous conditions and have treatment promptly administered.

OSHA Regulations on Heat Stress

OSHA doesn’t have any heat-specific safety regulations on the books, but the General Duty clause also applies to heat hazards. OSHA recommends employers adopt the heat safety standards published by The National Institute for Occupational Safety and Health (NIOSH).

There are several state-level and heat safety regulations, too – published in California, Colorado, Minnesota, Oregon and Washington.

There is momentum toward OSHA publishing heat-specific regulations. In fact, one was proposed in July 2024 – a rule that would require employers to enact specific safety provisions (additional breaks, additional health monitoring, etc.) when certain temperature thresholds are reached. It’s likely that OSHA will eventually publish safety regulations for heat hazards specifically, given the increased scrutiny in this area.

Heat Illness Prevention Strategies in the Workplace

There are many measures employers can implement to improve heat safety, including:

  • Better hydration and nutrition guidelines – Fluid and electrolytes are lost to excessive sweating, which leads to heat illness symptoms. Replacing both is essential to warding off heat exhaustion and heat stroke, and this starts with better hydration and nutrition. Specifically, choosing hydration and electrolyte-replacing foods and drinks, like fluid-rich fruits and sports drinks. Employers are responsible for providing workers with adequate water and breaks to replenish fluids. As the temperature climbs, workers will need water breaks more frequently and will need more water to prevent heat illness.
  • Monitoring workers’ health – Elevated temperatures will place additional stress on workers, and this can mean danger for workers with pre-existing health conditions.
    When conditions are hazardous, onsite safety personnel must be ready to step in and check worker vitals periodically to ensure any signs of heat illness are spotted immediately. High-risk workers with significant health conditions should be monitored closely and rotated to lighter duty, if possible.
  • Preparing an emergency response – OSHA recommends employers develop heat-specifical emergency action plans (EAPs) to ensure a rapid response if heat illness does emerge.
    An EAP should outline the treatment procedures responding personnel will take if a worker experiences heat illness. EAPs outline treatment and provide an inventory of emergency response resources (and their location) and contact information for a nearby hospital or emergency room. EAPs give workers the information they need to respond quickly and effectively.
  • Providing training and educational resources to employees – Once your organization has its heat safety standards in place, they must be reinforced through repeated training drills and safety-focused talk. Ultimately, all forms of workplace safety – including heat safety – are reinforced by top management, so the company’s leaders must take charge in practicing and emphasizing safety. Regular training sessions are an important way to do this.

The Right Resources and Tools Will Also Improve Workplace Heat Safety

The right heat safety resources can make the difference when a heat illness emergency occurs. These resources should be stored in a clearly marked area that all personnel are aware of. Emergency heat illness resources typically include electrolyte tablets, cool packs and wraps. Together, these can bring down dangerous body temperatures quickly and treat dehydration.

Even better, outfit workers with tools that they can use to monitor work conditions and protect themselves when working. One example is liquid crystal thermometers (LCTs) integrated into employee TWIC cards. LCTs provide an accurate temperature reading within seconds and weigh next to nothing, so they can be easily carried and stored. And for organizations on a tight budget, LCTs are low-cost solutions that encourage workers to take charge of workplace safety – something every organization will benefit from.

What Are The OSHA Requirements for Heat Safety

The Occupational Safety and Health Administration, or OSHA, is the governing body overseeing the implementation of workplace safety measures. It organizes these measures through various regulations, all of which employers need to be concerned with. As of yet, OSHA does not have particular regulations in place for heat safety, but that doesn’t mean employers can slide on protective measures. OSHA’s General Duty Clause requires employers to be aware of and remove recognizable hazards that are likely to cause serious harm or death to their workers. OSHA considers excessive heat, both environmental and labor-induced, to be among those recognizable hazards. As such, it is the employer’s responsibility to account for the heat and take the appropriate steps to neutralize its effects on employees.

OSHA Requirements For Heat SafetyWhat OSHA Recommends

OSHA may not have a regulation dedicated to heat safety, but it has published materials detailing how to best approach it. These materials should be of interest to any employer that wishes to maintain OSHA compliance regarding heat safety. OSHA recommends greater levels of awareness and intervention as the heat index climbs. The heat index takes into consideration both air temperature and relative humidity. As humidity rises, the body’s ability to wick off heat using sweat worsens, so it’s more difficult for workers to mitigate heat caused by labor. As air temperature and humidity rise, it is up to the employer to offset the increased danger with additional resources.

Some of the most important points of heat safety, from OSHA’s perspective, include:

  1. Provide workers with a shaded rest area – Once the heat index climbs above 90 degrees, heat illness becomes a real possibility. Lower heat indexes can also be a concern if the worker is outfitted with impermeable protective gear, including gear designed to protect against chemical or biological agents. As soon as the heat index passes the 90-degree threshold, or when workers are expected to don heavy, insulated gear, OSHA strongly recommends employers provide their employees with shaded rest areas. This area should be shaded at all times, so it should be comprehensive enough to keep the sun from intruding at any point of the day. It’s also best to set the rest area up where it will be unexposed to warm breezes, which can accelerate the onset of heat-related illnesses. A shaded tent is an example of an appropriate rest area. Its mobile design and contained environment is ideal for establishing a cool area, regardless of the location. Tents equipped with air conditioners or heavy-duty fans can offer the ideal base for workers in need of cooling.
  2. Provide workers with plenty of potable water – OSHA recommends water that is between 50 and 60 degrees, and between four and six cups of it every hour. Water consumption should begin before the worker notices thirst, as it may be too late to prevent dehydration once the worker becomes thirsty. There should always be drinking water available, so employers must have procedures in place to ensure supplies are replenished with regularity. Workers, and particularly workers who are new to working in the heat, should be encouraged regularly, and firmly, to drink plenty of water. Most incidences of occupational heat-related illnesses occur among inexperienced workers, as they may not be accustomed to working in the heat.
  3. Monitor workers continuously for signs of heat illness – When the heat index climbs above 90 degrees, supervisors should ensure that all heat safety measures are being observed. Shaded rest areas should be utilized, plenty of water should be consumed and other cooling methods taken advantage of. As the heat index climbs even higher, it is imperative that worksites have experts on heat-related illnesses available. These experts should be able to recognize the signs of heat illness right away and know how to administer first aid to workers experiencing symptoms. The expert should also recommend changes to work schedules in response to dangerous conditions. In short, there should be someone at the worksite who will ensure workers are safe and following protocols related to heat. At higher heat indexes, medical facilities should be available within minutes. If they aren’t, then it is the employer’s responsibility to have resources on hand to treat any heat illness that emerges. If the heat index climbs above 115 degrees, or if workers are fitted with heavy, insulated gear for long stretches of time, then additional, significant measures to prevent heat illness must be deployed. This includes physiologically monitoring workers, regularly checking their heart rate, temperature and other vitals that may indicate overheating. Workers should be acclimatized to an extreme environment like this prior to taking on a full workload.
  4. Provide cooling measures, for both preventative and curative situations – When the heat index passes 103 degrees, it’s important that employers consider personal cooling methods. This will protect workers who must remain in the sun for extended periods of time, and workers who cannot access rest areas as often. Personal cooling may be as simple as clothing that has been dampened with water, or something a bit more advanced, like misting stations. Reflective clothing and vests with cooling packs are also effective. If heat illness does appear, then immediate steps must be taken to prevent permanent injury (or death) to the worker. This includes rapid application of wet cloths, transport to a cooled room, administering fluids and immersion in an ice water bath. As this scenario may cause unconsciousness, it is critical that measures are in place to handle an unconscious person.
  5. Pair workers together while they are exposed to heat – The signs of heat illness can creep in slowly and may not be noticed before they become serious. Using a “buddy system” can help worksite managers detect heat illness faster, which may make the difference in keeping workers safe.

Heat-related illnesses are potentially deadly, and it is up to employers to neutralize hazards before they materialize. Adhering to OSHA recommendations will go a long way in doing this as they provide an excellent starting point.