What Is the AIHA Heat Stress Application?

The AIHA Heat Stress application is a mobile app (iPhone and Android) developed through a partnership by AIHA and East Carolina University intended for us in preventing heat related illnesses through recommended health measures for two specific user types. It is currently available for free download in the Google Play Android App store and Apple App store.

Our target users are:
1. Outdoor workers
2. Managers of outdoor workers

The key technical differentiator for this application is its focus on an adjusted Wet Bulb Globe Temperature (WBGT) calculation to inform risk and provided needed action steps. The WBGT calculation algorithm is the core mechanism powering our app's various functions.

To understand the importance WBGT and its use in monitoring heat stress, we recommend reading Joseph G. Allen's recent Washington Post editorial, "We need to change the way we think about outdoor temperatures. The public should adopt the 'wet-bulb globe temperature.'"

Thermal stress, also known as heat stress, is one such environmental factor that can wreak havoc on employee health in nearly any workplace. And not just outdoor work sites! Establishing evidence-based heat stress protocols with the help of OEHS experts is an important first step in safeguarding both indoor and outdoor workers from the risks of heat stress.

Workplaces at Greatest Risk

Studies show that workers experiencing some form of heat stress do not perform their job as efficiently as workers who are not impacted by this form of heat exposure. In fact, one Australian study reported that approximately 1,214 workers surveyed were 35% less productive on days they indicated experiencing heat stress. The impact of occupational heat stress is far-reaching with no signs of slowing down. It is estimated that heat stress could bring down global productivity levels by the equivalent of 80 million full-time jobs by the year 2030.

While heat stress commonly occurs in hot outdoor temperatures, there are many workplace situations that can lead to heat-related injuries, including:

• High outdoor heat exposure
• Poor ventilation
• Wearing Personal Protective Equipment (PPE)
• Low accessibility to fluids
• Heat stressors on the job such as high physical exertion, limited rest breaks, productivity or economic incentives that do not allow self-pacing (i.e., working at your own pace)
• Poor personal physical fitness
• Workers unacclimatized to heat

Given these wide-ranging situations, it is easy to see how nearly any workplace can pose a certain level of risk from heat stress. However, the following industries are examples of environments that pose the greatest threat to worker health:

• Agriculture
• Construction
• Oil & Gas
• First responders/firefighters
• Utility companies
• Manufacturing plants
• Postal workers (most OSHA-reported severe injuries)
• Athletes (football lineman most susceptible to heat stress due to conditioning issues)

How Heat Stress Affects Productivity

Numerous studies show how heat stress can have significant negative impacts on productivity. In fact, predicted global costs from lost worktime due to occupational heat stress are $2.4-$2.5 trillion in 2030 and up to 4% of GDP by 2100. With the continuous rise in extreme global temperatures due to climate change, the adverse effects of extreme heat on workers will progressively get worse. For example, the global costs associated with lost worktime due to heat were $280 billion USD in 1995 and had risen to $311 billion USD in 2010 (equivalent to 0.5% of GDP) and continue to rise.

Know Your Employees’ Heat Stress Risks

Nearly any workplace can present heat stress health risks for workers. Some workplace situations are obvious, such as a construction worker building homes in the sweltering summer heat; other workplaces are not as obvious, such as factories with poor ventilation that create a potentially hazardous situation. Occupational and environmental health and safety (OEHS) experts have identified the following industries as examples of work environments that pose the greatest heat stress risks for workers:

• Agriculture
• Construction
• Oil & Gas
• First responders/firefighters
• Utility companies
• Manufacturing plants
• Postal workers (Most OSHA-reported severe injuries)

It is also important to recognize the most common misconceptions about heat stress to fully understand your personal risk.

Establish Evidence-Based Heat Stress Management Guidelines Companywide

The best way to protect workers from the real threat of heat stress year-round is to work with OEHS experts to evaluate the heat stress risks in your workplace. Based on their assessment, OEHS experts will recommend evidence-based strategies for minimizing these risks with all employees. For example, one study examining the benefits of working in shaded areas or altering work shifts found that moving a working shift 2 hours earlier to avoid heat stress reduced costs by 33%.

Examples of Strategies in a Heat Stress Management Plan include:

1) Heat Safety Education (on-boarding and annual training)

2) Hydration Accessibility

3) Heat Acclimatization

4) Activity Modification (work-to-rest ratios) Dictated by the Environment

5) Implementing Shade and Body Cooling Product Accessibility

6) Emergency Policies and Procedures for Heat-Related Illnesses

7) Physiological Monitoring

How OEHS Professionals Can Help

OEHS professionals can work with you to design a heat stress plan specific to your industry and workforce. From conducting a comprehensive workplace audit to surveying employees about the impact of heat stress on their health and performance, an OEHS expert can help you establish evidence-based protocols to reduce risks.

The AIHA, the association for scientists and professionals committed to preserving and ensuring occupational and environmental health and safety in the workplace and community, offers a consultants directory where employers can search for OEHS experts in their communities.