It's not just those in hot countries who deserve a siesta, says a sleep expert. Fiona Kerr, a neural specialist at the University of Adelaide in Australia, has advocated that we all take afternoon naps to improve functionality.These naps would often fall during the working day.Kerr told the Daily Mail: " The best nap is really the 15- to 30-minute nap. It increases alertness, memory, cognition and mood."She is an expert on short sleeps and their effect on cognitive function.story_article_left1"Naps are good for people because they serve as a cleaning-the-inbox function."If you have regular naps, you will store, retain and recall information faster and more effectively."Even if you don't sleep you'll feel refreshed. The other week I curled up under my desk for 20 minutes in order to get a small amount of shuteye."A nap is like a shower for your brain," she said.But, said Kerr, it was important not to have a full-blown slumber of 30 to 60 minutes because that sent a wrong signal to the brain.Research has suggested a nap a day could save your life. A midday snooze doesn't just have the power to revive - it could reduce blood pressure and prevent a future heart attack.Research involving almost 400 middle-aged people found that those who had a nap at noon later had lower blood pressure than those who stayed awake through the day.The findings, presented at the European Society of Cardiology annual conference in London, showed pressure was lower both when awake and later, during their night-time sleep.The small difference - of around 5% - was enough to have a significant impact on rates of heart attack.A top French think tank also recommended a 15-minute nap after lunch. Dr Jean-Pierre Giordanella, the co-author of a report on sleep, said offices should have dedicated napping rooms...