Name: Napping.

Age: Ancient. Before drugs, it was all we had.

Appearance: Like sleep, but shorter.

How much shorter? Well, that depends. A power nap is generally reckoned to last between 10 and 20 minutes. A catnap is a bit longer, say 20 to 25 minutes. A decent Spanish siesta could be 30 minutes or more.

Only 30 minutes? But their shops are shut all afternoon! “Siesta” can refer to the whole period of daily downtime – generally from 2pm to 5pm – as well as the shorter nap that takes place within it.

I’m not sure I could live that way, having naps on purpose. You have naps by accident?

Almost every day, straight after lunch. How do you cope at work?

I have pictures of eyeballs cut from magazines glued to my glasses. I guess that counts as a power nap.

I certainly find it energising. But maybe a proper Mediterranean siesta would be even better for me. Not necessarily. Short naps can be restorative, but any snooze longer than 25 minutes risks tipping into stage 3 sleep – a deep slumber which can leave you feeling groggy for hours afterwards.

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If you haven’t got to be back at work till 5, who cares? Unfortunately it could also affect your health in other ways.

Such as? A study published last week of 3,000 people from the Spanish region of Murcia found that, compared with non-nappers, those who took siestas of 30 minutes or longer were more likely to have a higher body mass index.

You mean sleeping makes you fat? It’s just as possible that being overweight makes you sleepy, but the long siesta was also associated with higher blood pressure and a variety of conditions related to heart disease and diabetes.

All that from excessive napping? It’s not clear whether lifestyle factors – staying up late, smoking, overeating – are the cause of the ill-health and the long siestas, but previous studies have shown a causal link between siestas and abdominal obesity.

Do the Spanish know about this sleeping health timebomb? It’s probably not as bad as you think. Sixty per cent of Spaniards surveyed said they never take a siesta.

Never? Then why can’t I buy postcards until after sundown? When was the last time you went to Spain?

I’ve never been to Spain. So, briefly, should I be napping? Exactly – briefly.

Do say: “To die, to sleep, perchance the former as a result of the latter.”

Don’t say: “The optimal nap lasts 25 minutes, coincidentally the length of the average Zoom meeting.”