The courtroom was warm, the sun was shining in through the window and it was that time of the afternoon when time drags and energy levels and eyelids tend to drop. Not surprising then that John Harrison elected to close his eyes for a few minutes.

Unfortunately, he is a magistrate and was in the middle of hearing the case of a teenager charged with assault. The defendant's mother complained. The case was halted and will be retried. “I was not asleep,” Harrison explained last week. “But I rested my eyes for five minutes or so. It was just a normal reaction in the middle of the afternoon.”

Indeed. Harrison's mistake was not closing his eyes. It was failing to inform all those at Lancaster Magistrates' Court that he was going to do so and not encouraging them to follow his lead.

We all need a good nap. Just look at me. At the time of writing it is almost 2.30pm. It's been almost 2.30 for an hour at least. My eyes are so heavy I can hardly lift them to look at the clock. My head weighs about a tofhfdndknkkkkkkkkkkkkkkkkkkk

Waah. Hoo. Must have dropped off for a second then. There you go. Proof. I need a nap. And there's plenty of scientific evidence to back me up. A few years ago research at Harvard University found that “burnout” sets in as the day wears on and a nap of an hour can restore mental performance to morning levels.

Other researchers suggest that shorter naps are beneficial. I once had my sleep monitored for a week and the results analysed by Professor Jim Horne, the world-renowned expert at Loughborough University's Sleep Research Centre. He advocated a daily nap, but suggested it should be no longer than 15 minutes.

My experience bears that out. Although I enjoy a nap all too rarely these days, just ten minutes or a quarter of an hour can be extremely refreshing. Any more than that and waking up is hard and you feel groggy.

A nap may even be good for your long-term health. A study in Greece found that those who took at least three naps a week were 37 per cent less likely to die from heart disease.

But you don't need data. You know napping makes sense. Especially as we adjust to the clocks going forward. That's why it's National Nap at Work Week. The perfect time to kick off a napping revolution.

The trouble is that napping during the working day is hard to do. That's not the case on the Continent. In France the siesta is regarded as an essential part of national life and absolutely necessary to the pursuit of extra-marital affairs.

It was Noël Coward who said that Englishmen “detest a...siesta”. This is a little odd, given that one of the greatest of all Britons was a champion of the nap. How else would Winston Churchill have been able to stay up all night plotting victory? After a boozy lunch he would get into his pyjamas for a nap in his quarters in the subterranean Cabinet War Rooms. His staff thought his schedule very eccentric.

If anything, napping has traditionally been even more frowned upon in the crucible of capitalism. The American Protestant work ethic does not allow for a little sleep in the middle of the afternoon. That may be changing, however. And not because of the credit crunch. The siesta has been rebranded as a “power nap”, that can improve productivity. In New York you can even book into sound-proofed pods for a daytime kip.

The important thing is not to be caught napping. That can look like you are too hungover or old for the office and give the boss an excuse to give you a hard time. No one needs that at the moment. You need to announce to your colleagues that you are going to take 40 winks, and then not exceed the time you have set yourself. Let them witness the uptick in your creativity that follows.

But where to kip? If you can persuade your boss to set up some little beds, like at nursery school, then you are clearly one of Britain's great salespeople. A Cornish company, Worlds Apart, produces the ReadyBed, which is inflatable and includes a built-in sleeping bag and pillow. But you need space for that.

A hammock, slung between the filing cabinets, would be fun and take up less space.

Or how about under the desk? I can recommend this. When my kids were babies I tried this a few times. I didn't have quite the set-up that George had in the classic episode of Seinfeld, where he built a mini bedroom complete with shelf for an alarm clock, under his desk. But I took a cushion down there and once I stopped gagging on all the fluff it wasn't too bad.

Alternatively, just recline in your chair, close your eyes and don't worry about the odd colleague laughing as you drool. If your boss complains show him or her this article. Refer your employer to the estimable Journal of Neuroscience. A little sleep, after all, can go a long way.

How to take 40 winks

1. Best not to nod off right on deadline or first thing in the morning. The first looks like carelessness, the second like too many mojitos. Research shows that the body is at its lowest ebb in the middle of the afternoon. That is nap time.

2. Tell your colleagues. The worst possible nap is a sneaky nap. If attitudes to workplace snoozing are to be overhauled then you have to be open about it. Getting caught taking 40 winks in the cleaners' cupboard or trying to sleep with your head propped up as if reading a book on the desk makes bosses suspect that you are work-shy. Explain the benefits of napping and tell those around you: “OK, I'm just going to take my nap.”

3. Select a location. If your boss has yet to lay on a dormitory, see if you can hook up a hammock. Alternatively, try nesting under the desk. Or take your chair to a corner where no one will be offended by your snoring and junior colleagues will be less tempted to flick things at you. Never take your nap in a locked lavatory.

4. Accessorise. Plug in your iPod with some calming music or whale song. Eyemasks make all the difference and those inflatable travel pillows look silly, but are handy.

5. Set your alarm. Plan to sleep for only 15 minutes. Do not take advantage of your boss, however enlightened.

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