For most of her life, Carol Smith has never had much trouble with sleep. But all of that changed when she began working a 12-hour graveyard shift -- from 6 p.m. to 6 a.m. -- as a 911 dispatcher.
At times, she says she's had to struggle to stay awake and alert on the job. "It was very difficult for me," she recalls. "I'd get real fidgety, and doing any kind of paperwork was hard because it was so tough to concentrate. At times, I felt so uncomfortable that I just wanted to crawl out of my skin."