This applies not only to night shifts but also for people working other irregular shifts, says Professor Skene.

BBC: RELATED BBC SITES

Shift workers whose sleep is disrupted by working at night or working long or irregular hours also face increased risks.

CNN: How to combat drowsy driving

Additional work, especially if you are currently working part time or have irregular hours, can help you develop new skills and expand your network.

WSJ: Make a Second Job Work for You

Women's wages lag one-third behind men's, partly because they take irregular jobs, partly because they stop working to start families, and also because women are not given the same opportunities as men to follow managerial careers.

ECONOMIST: Insiders and outsiders