According to the Occupational Safety and Health Administration, fatigue is the body’s way of signaling to the brain that it is time to slow down and rest. Unfortunately, many Americans fail to heed the body’s warnings and continue to work long hours, take on irregular and extended shifts and operate on little sleep. If you run on too much caffeine and too little sleep, you risk disrupting your body’s natural rhythms and increasing your level of fatigue, which can result in stress, lack of concentration and increased risk of making mistakes in the workplace.

Though workplace fatigue can affect any population, it is particularly common among workers who work extended and irregular shifts. Industries commonly affected by this phenomenon include transportation, health care, emergency response, law enforcement, construction, military, oil and gas extraction and hospitality.

Workplace fatigue is often both costly and dangerous. Exhaustion often leads to an increased risk for illness and injury. In fact, accident and injury rates are 30% greater during night shifts than they are during the day shifts; they are 18% higher during evening shifts as well.

Additional findings show that individuals who work more than 12 hours a day have a 37% increased risk of sustaining an on-the-job injury. One study of nearly 3,000 medical residents show that for every extended shift worked during a month period, a resident’s risk of being involved in a motor vehicle accident during his or her commute increased by 16.2%.

Research reveals that workplace fatigue is also a contributing factor in major adverse events. For instance, exhaustion played a role in the 2005 explosion of the Texas BP refinery, the explosion of the space shuttle Challenger and Chernobyl. Errors in patient care also increase as health care workers take on more hours.

Workplace fatigue is a costly problem. According to OSHA, it is directly linked to increased costs from illness, injury and lost productivity. Findings also link it to increased workers’ compensation costs. On an annual basis, researchers estimate that on-the-job exhaustion costs U.S. employers $136.4 billion.