Summer is on its way, and the chance to jet off to sunnier climes. But do think carefully before you book your holiday for the following year - and try not to worry if you're 20,000 ft up at midnight on 21 August 1999. They will have sorted out the millennium bug by then. . . probably.

If not, warns the Institution of Electrical Engineers, positioning systems used to track aircraft and shipping will fail, believing the next day to be 6 January 1980 and providing a terrible foretaste of the mayhem to come. And that's just the first in a series of problem dates stretching into the next century.

There are masses of web sites dealing with year 2000 problems - hundreds of thousands, according to the British Computer Society - many of relevance to the health service. In addition to the two already mentioned here, of course, the NHS Executive Year 2000 Team is the organisation to start with.

In common with a number of other official sites, including the DTI's Busting the Bug and the US Food and Drug Administration's Center for Devices and Radiological Health, it offers a database of supplier information. I would like to tell you if it's any good, but I waited and waited and couldn't get in.

Since the millennium bug affects anything with an internal clock or running date-aware software, the Medical Devices Agency also takes an interest.

Bearing in mind the shortness of the timescale, it might help if it updated its site, but its advice is if you haven't heard from suppliers by now, complain.

Even if you survive to 1 January 2000, don't get complacent. The IEE helpfully lists problems to come at the end of February 2004, some time in 2024, in 2030 (when some Microsoft products revert to year zero), and in January 2038.

But if you make it to 1 March 2101, you're home and dry.