Researchers at the University of Massachusetts recently released what is perhaps the largest study to date on the relationship between overtime and workplace injuries, finding that those who work extra hours are 61 percent more likely to be injured on the job than those who do not. The stress of working long, non-voluntary overtime shifts can also lead to chronic pain and fatigue, no matter how much money a worker is receiving for the extra hours.
See "The Workplace: Overtime doesn't always pay", Thomas Fuller, International Herald Tribune, September 6, 2005