With summer quickly approaching, employers need to be aware of the risk of heat stress and how to prevent it. Excessively warm work conditions in industrial facilities and outside in construction sites not only pose dangers to employees but can also keep your facility from being OSHA compliant.

While construction workers account for more than one-third of work related heat-deaths, other industries exposed to hot environments include public administration, agriculture, forestry, fishing and hunting, and mining.

Worker with face mask outside

Heat stress is defined as the total amount of heat the body encounters. This includes not only the temperature and humidity in the environment, but also heat from work processes and machinery, inadequate air circulation, internal metabolic processes, and heat generated by muscles from physical exertion. These conditions are also considered to be risk factors that can increase an employee’s risk for a heat-related illness.

Certain workers are at a higher risk of heat stress, including those who are 65 years of age or older, are overweight, have heart disease or high blood pressure, or take medications that can be affected by extreme temperatures (such as medications for colds or blood pressure). Additionally, while older folks are certainly at an increased risk for heat illness, a recent study found younger male workers to be at greater risk than other demographic groups. Other heat-related risk factors include dehydration, PPE that can trap heat close to the body, pregnancy, lack of acclimatization, and previous illnesses related to heat stress.

Risks of Heat Stress

Heat stoke is arguably the most dangerous and severe forms of heat-related illnesses and in some cases can even be fatal. If the early signs of heat stroke are missed or the employee does not receive proper medical attention, it can result in seizures, loss of consciousness, and organ failure, ultimately leading to death.


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According to the CDC, issues associated with heat stress and acute kidney injury, loss of kidney function, and chronic kidney disease are also emerging. Researchers have recently identified heat stress as the strongest risk factor when it comes to nontraditional origins of chronic kidney disease, and other studies have found chronic kidney injuries in mail and package delivery workers as well as agricultural workers.

Another serious risk of exposure to extreme heat is heat exhaustion with symptoms including disorientation, fatigue, fainting, profuse sweating, nausea, and rapid heartbeat. For anyone experiencing heat exhaustion or heat cramps (another heat-related syndrome, though not as serious), rest in an air-conditioned room is crucial.

Preventing Heat-Related Illnesses

There are many different types of workplace controls businesses can use to mitigate the hazards of heat stress, and safety can be achieved through a complete heat stress program, which includes identifying and assessing risk, limiting exposure reducing metabolic heat load, acclimating workers to working in hot environments, and more. Below are some ways employers can prevent illnesses caused by heat stress which can also be tailored for specific worksites:

  • Frequent hydration: One of the most important risk factors when it comes heat illness is dehydration. To combat this, OSHA recommends employees drink a cup of water every 20 minutes while working in the heat.
  • Training: Workers should be properly trained to recognize early signs of heat stroke and other illnesses so medical treatment can be sought as quickly as possible. It’s also important this information is effectively communicated to the entire workforce. For instance, there may be language barriers with farm workers from other countries, and training would be best delivered in their native language.
  • Acclimatization: A major risk factor for heat-related illnesses is lack of work experience and acclimatization—gradually increasing exposure to a hot environment so the body can better maintain a safe and stable body temperature. For acclimatizing workers, employers can gradually increase the time spent in hot conditions and new workers should be acclimated as they begin their job.
  • Medical care: Procedures should be in place for contacting emergency medical services if an employee begins to experience serious symptoms of a heat-related illness.

COVID-19 and Heat Stress

Many companies this past year have had to make major changes to their work environment while implementing safety and health recommendations from the CDC’s Interim Guidance for Businesses and Employers. While these changes have been critical to slowing the spread of COVID-19, these alterations to working environments can impact the risk level of illness caused by heat stress. The CDC recommends workplaces to consider the following risks:

  • Acclimatization if your workplace has been closed
  • How wearing face covering affects the body
  • Social distancing causing increased physical activity
  • Increased time in a hot environment to catch up on work

It’s important for employers to make any necessary changes to their heat illness prevention program to protect workers from exposure to heat and COVID-19.

More than two-thirds of the country are expected to reach record temperatures this summer. Before exposing workers to extreme temperatures in the workplace, plan ahead and make sure your business has a comprehensive heat stress program in place before workers are exposed to extreme heat.

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