Extreme heat is one of the deadliest weather-related hazards in the United States and a growing workplace safety concern for employers. In recent years, heat waves have become more frequent, longer-lasting and more intense. In fact, 2025 ranked as the fourth-warmest year on record for the contiguous United States, and the nine warmest years on record have all occurred since 2012.
The impact extends beyond outdoor job sites. OSHA estimates workers suffer more than 3,500 heat-related injuries and illnesses each year, highlighting the importance of proactive heat illness prevention efforts.
Understanding heat-related risks, OSHA expectations and practical prevention strategies can help employers protect employees and reduce the likelihood of serious injuries or fatalities.
While any employee can experience a heat-related illness, some workers face a greater risk than others depending on their work environment, physical demands and level of heat exposure. Understanding where risks are most likely to occur can help employers take proactive steps to protect workers before temperatures become dangerous.
Employees who work outdoors often face the highest risk of heat-related illness because they may be exposed to direct sunlight, high temperatures and physically demanding tasks for extended periods. Construction workers are particularly vulnerable. According to the EPA, construction workers accounted for approximately one-third of occupational heat-related deaths between 1992 and 2022.
Industries commonly affected include:
Among these industries, construction consistently experiences some of the highest rates of heat-related illnesses and fatalities due to prolonged outdoor exposure and physically demanding work.
New employees and workers returning after an extended absence may face an even greater risk until they have had time to acclimatize to hot working conditions.
Heat-related hazards are not limited to outdoor job sites. Employees working indoors can also be exposed to dangerous temperatures, particularly in facilities where heat-generating equipment, limited ventilation or seasonal temperature increases create hot working conditions.
Indoor employees who may be at increased risk include those working in:
Employees performing strenuous physical labor, wearing heavy personal protective equipment or managing certain medical conditions may also be more susceptible to heat-related illnesses.
Because heat-related illnesses can develop quickly, employers should evaluate workplace conditions, identify employees who may be at greater risk and implement appropriate prevention measures before heat-related emergencies occur.
As temperatures continue to rise across the United States, employers face increasing pressure to protect workers from heat-related illnesses and injuries. OSHA has increased its focus on workplace heat hazards through enforcement, inspections and outreach efforts designed to reduce heat-related illnesses and fatalities.
OSHA updated its National Emphasis Program (NEP) for Outdoor and Indoor Heat-Related Hazards on April 10, 2026, directing enforcement efforts toward 55 industries identified as having the highest risk of heat-related hazards.
According to OSHA, the updated program is designed to focus agency resources where they can have the greatest impact, targeting industries with elevated rates of heat-related illnesses, previous heat-related citations and documented workplace heat hazards.
Compliance officers may conduct inspections in high-risk industries during National Weather Service heat advisories and warnings while continuing outreach and compliance assistance efforts to help employers strengthen heat illness prevention programs.
Under OSHA law, employers are responsible for providing workplaces free of known safety hazards, including excessive heat exposure. Early interventions include providing water, rest, shade, training and acclimatization procedures for new or returning employees.
OSHA's National Emphasis Program gives the agency authority to initiate heat-related inspections and investigations. Employers should be aware that:
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Even though heat-related illnesses and fatalities are largely preventable, OSHA reports that thousands of workers suffer heat-related illnesses each year while working in hot or humid conditions, and some cases result in death.
The human body relies on sweating and increased blood flow to the skin to regulate its internal temperature. However, when temperatures are high, humidity levels are elevated or physical activity is strenuous, the body may struggle to cool itself effectively. If lost fluids and electrolytes are not replaced, the risk of heat-related illness increases.
As the body stores more heat, core temperature and heart rate rise. Workers may experience fatigue, dizziness, headaches, confusion, irritability, reduced concentration or nausea. Without prompt intervention, heat exhaustion can progress to heat stroke — a life-threatening medical emergency that requires immediate treatment.
Heat exposure can also increase the likelihood of workplace accidents and injuries. Factors such as fatigue, impaired judgment, dizziness, sweaty hands and fogged safety glasses can contribute to falls, equipment incidents and other safety hazards on the job.
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Employers whose workers are working in extreme heat have a legal, moral and fiscal obligation to protect them. Take these steps to prevent heat stress and keep both workers and bottom lines healthy:
Employers should also monitor local weather conditions and heat index levels throughout the day. Resources such as the OSHA-NIOSH Heat Safety Tool app can help supervisors assess heat risks and determine when additional precautions may be necessary.
Heat stress is a serious health concern that can occur when your body can't adequately cool itself, often as a result of prolonged exposure to excessive heat or physical exertion in high-temperature conditions.
This stress can lead to conditions like heat exhaustion and heat stroke, which if left untreated, can be life-threatening.
Heat stress occurs when the body is unable to cool itself effectively through sweating and other natural processes. Prolonged exposure to high temperatures, humidity or strenuous physical activity can increase the risk of heat-related illnesses, including heat exhaustion and heat stroke.
If not managed properly, heat exhaustion can progress to heat stroke.
If symptoms persist or worsen, seek medical attention immediately.
Heat stroke, on the other hand, is the most serious heat-related illness and is considered a medical emergency. It occurs when the body's temperature rises rapidly, the sweating mechanism fails and the body cannot cool down. This condition can cause death or permanent disability if not treated promptly.
If you suspect someone has a heat stroke, call 911 or your local emergency number immediately. While waiting for help, move the person to a cooler place, help lower their temperature with cool cloths or a cool bath, but do not give the person anything to drink.
Heat stroke requires professional medical treatment and time is of the essence.
Heat-related illnesses can often be prevented through proper planning, training and workplace heat safety practices. Employers should provide access to water, rest and shade, monitor heat conditions, allow workers to acclimatize to hot environments and train employees to recognize the signs and symptoms of heat-related illness. Having a clear emergency response plan in place can help ensure workers receive prompt assistance when needed.
Know and watch for symptoms of heat-related illness during hot weather and plan what to do in an emergency. Quick action can save lives.
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Heat illness prevention requires more than monitoring the forecast. Employers need clear policies, employee training, emergency response procedures and practical strategies for protecting workers in hot environments.
Axcet HR Solutions helps employers strengthen workplace safety programs, navigate OSHA requirements and build safer work environments. If you need assistance evaluating heat-related workplace risks or developing prevention strategies, our team is here to help. Reach out to us today >>
Written by
Sam Hihn is a Safety and Health Consultant at Axcet HR Solutions, where he helps businesses build safer, more compliant workplaces through practical, hands-on risk management strategies. He works closely with client organizations to identify hazards, strengthen safety practices, and implement programs that protect employees while supporting operational efficiency.
Sam partners directly with business leaders and frontline teams to assess workplace environments, equipment, and processes, ensuring alignment with OSHA standards and other regulatory requirements. He develops customized safety and health programs tailored to each organization's needs and provides guidance through OSHA inspections, citation responses, and corrective action planning—helping clients navigate compliance with clarity and confidence.
A key part of Sam's work is translating complex safety requirements into clear, actionable steps. He conducts safety training, supports incident investigations to determine root causes, and delivers practical recommendations to prevent future issues. His approach focuses not only on meeting regulatory standards but on building sustainable safety practices that become part of everyday operations.
With a background in manufacturing and safety roles, Sam brings real-world perspective to the challenges employers face. He is known for his approachable style, attention to detail, and commitment to helping teams take ownership of workplace safety. Through his writing, Sam shares actionable insights and guidance to help employers reduce risk, improve compliance, and create safer environments where employees can thrive.
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