Spring has sprung and summer is nearing. Along with the rising temperatures are rising incidents associated with heat-related illnesses and disorders, which must be addressed by safety practitioners.

Unlike other weather-related hazards such as hurricanes, tornadoes and thunderstorms, which rightfully garner a lot of attention from emergency and disaster preparedness personnel, the natural hazard of heat is sometimes overlooked.

Yet, according to the National Weather Service – U.S. Natural Hazard Statistic’s Web site, on average, heat kills more people than other natural hazards. An average of 235 people die each year from heat based upon statistics from 1993–2002. This number is far greater than the averages for tornadoes, hurricanes or lightning, which total 59, 17 and 53, respectively, for the same period. Although this data includes incidents outside of the workforce, it illustrates the importance of addressing heat exposures.

Heat plus other factors

When hot weather conditions are combined with other factors, such as physical work, loss of fluids, fatigue, and so on, disorders associated with heat stress can become problematic. Heat stress disorders can lead to decreased productivity, illnesses, disabilities and even death. Common heat disorders include heat rash, cramps, fainting, heat exhaustion, heat stroke and death. (Details of these disorders are described in OSHA’s Fact Sheet 95-16, available at www.osha.gov.)

Safety professionals and organizations must be proactive in preventing and controlling heat disorders. A risk management approach, including identifying and analyzing loss exposures and developing alternative techniques for risk control, can be utilized. Heat exposures can be identified by various methods including physical inspections, job hazard analyses, questionnaires, PPE assessments and temperature readings.

Other methods to monitor heat exposure include monitoring weather conditions such as forecasts and warnings by the National Weather Service and monitoring the heat index. The heat index is the temperature the body feels when heat and humidity are combined.

Assess the risk

Figure 1, a chart from the National Weather Service, shows the heat index (HI) that corresponds to the actual air temperature and the relative humidity. As detailed on the National Weather Service - NOAA Web site, the chart is based upon shady, light wind conditions. Therefore, exposure to direct sunlight can increase the HI, by up to 15°F.

Once the heat index (HI) is determined, a table available from the National Weather Service can be used to assess the risk. Figure 2 is an illustration of the table available from the National Weather Service -NOAA Web site. This table can be used to identify the risk associated with heat disorders based upon the derived heat index.

Risk control techniques

Once exposures and risks are identified, risk control techniques such as exposure avoidance, loss prevention and loss reduction should be implemented to prevent and control loss incidents. Exposure avoidance involves never undertaking the loss exposure or completely eliminating the exposure. Examples of this technique include:

• Isolate workers from heat sources.
• Eliminate or postpone non-essential jobs or operations in hot environments.
• Mechanization of operations that eliminate the need for workers to operate in the hot environment.
• Provide air-conditioned environment to eliminate heat exposure.

Loss prevention techniques are geared toward preventing the loss, and loss reduction techniques are implemented to reduce the severity of loss incidents. These techniques include engineering controls, administrative controls, work procedure controls and more. Examples of these controls include:

• Acclimatization;
• Rest breaks in a cool, shady location;
• Utilization of ventilation systems, spot cooling, fans or the like;
• Shielding of heat sources;
• Schedule work during cooler temperatures;
• Teach employees and supervisors the signs and symptoms of heat-related illness so they can respond quickly;
• Utilize teams so that employees can monitor one another;
• Drink cool water — five to seven ounces every 15 minutes is suggested;
• Avoid alcoholic and caffeinated beverages;
• Eat light and avoid hot foods;
• Salt replacement may be needed, however avoid salt tablets. Workers should consult with their physicians to determine how sodium can be introduced;
• Wear light, loose-fitting, breathable clothing;
• Provide such PPE as cooling vests, air-supplied equipment, and so on;
• Implement job rotation.

Once programs and controls are implemented to address the identified heat exposures, monitor and assess work conditions to ensure that objectives are being achieved and that workers are adequately protected to prevent injuries or illnesses.