Dead tired or dead drunk? Fatigue kills - Test Thyself

There are products you can use to test your own alcohol level. We tried AlcoSense (£59.99, www.alcosense.co.uk) and it proved to be accurate when compared with TRL's readings. If anything, the detector slightly overestimated alcohol levels.

AlcoSense is marketed as a tool to help you judge if you're safe to drive the morning after.

As with any such device, the danger is that drivers may use it straight after a few drinks and have as much alcohol as they can get away with legally, if not safely.