A siesta (ˈsjesta) is a short nap

Nap

A nap is a short period of sleep.Nap may also refer to:-Politics:* National Action Party , a political movement* National Action Plan on the Elimination of Child Labour...

 taken in the early afternoon, often after the midday meal

Meal

A meal is an instance of eating, specifically one that takes place at a specific time and includes specific, prepared food.Meals occur primarily at homes, restaurants, and cafeterias, but may occur anywhere. Regular meals occur on a daily basis, typically several times a day...

. Such a period of sleep

Sleep

Sleep is a naturally recurring state characterized by reduced or absent consciousness, relatively suspended sensory activity, and inactivity of nearly all voluntary muscles. It is distinguished from quiet wakefulness by a decreased ability to react to stimuli, and is more easily reversible than...

 is a common tradition in some countries, particularly those where the weather is warm.

Since the siesta is the traditional daytime sleep of Spain

Spain

Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...

, and through Spanish influence, of many Latin America

Latin America

Latin America is a region of the Americas where Romance languages  – particularly Spanish and Portuguese, and variably French – are primarily spoken. Latin America has an area of approximately 21,069,500 km² , almost 3.9% of the Earth's surface or 14.1% of its land surface area...

n countries and in the Philippines

Philippines

The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...

, the word siesta has been taken from Spanish

Spanish language

Spanish , also known as Castilian , is a Romance language in the Ibero-Romance group that evolved from several languages and dialects in central-northern Iberia around the 9th century and gradually spread with the expansion of the Kingdom of Castile into central and southern Iberia during the...

, from the Latin

Latin

Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 hora sexta – "the sixth hour" (counting from dawn, therefore noon, hence "midday rest"). Einhard

Einhard

Einhard was a Frankish scholar and courtier. Einhard was a dedicated servant of Charlemagne and his son Louis the Pious; his main work is a biography of Charlemagne, the Vita Karoli Magni, "one of the most precious literary bequests of the early Middle Ages."-Public life:Einhard was from the eastern...

's Life of Charlemagne recounts the emperor's summertime siesta: "In summer, after his midday meal, he would eat some fruit and take another drink; then he would remove his shoes and undress completely, just as he did at night, and rest for two or three hours."

Factors explaining the geographical distribution of the modern siesta are mainly high temperatures and heavy intake of food at the midday main meal. Combined, these two factors contribute to the feeling of post-lunch drowsiness. In these countries, the heat can be unbearable in the early afternoon, making a midday break at home ideal. In many areas with this habit, it is common to have the largest meal of the day in the very early afternoon, as is practical and common in cultures dominated by agriculture.

The original concept of a siesta seems to have been merely that of a midday break intended to allow people to spend time with their friends and family. It has been suggested that the long length of the modern siesta dates back to the Spanish Civil War

Spanish Civil War

The Spanish Civil WarAlso known as The Crusade among Nationalists, the Fourth Carlist War among Carlists, and The Rebellion or Uprising among Republicans. was a major conflict fought in Spain from 17 July 1936 to 1 April 1939...

, when poverty

Poverty

Poverty is the lack of a certain amount of material possessions or money. Absolute poverty or destitution is inability to afford basic human needs, which commonly includes clean and fresh water, nutrition, health care, education, clothing and shelter. About 1.7 billion people are estimated to live...

 resulted in many Spaniards working multiple jobs at irregular hours, pushing back meals to later in the afternoon and evening. However, this hypothesis sounds unlikely, considering that the siesta tradition was very common in Latin America and other countries with Hispanic influence, much before the Spanish Civil War.

Protection from the sun

A siesta takes place when the sun is at its highest point. This is when the sun's ultraviolet radiation is at its peak at midday. Prolonged exposure to ultraviolet radiation may result in sunburn

Sunburn

A sunburn is a burn to living tissue, such as skin, which is produced by overexposure to ultraviolet radiation, commonly from the sun's rays. Usual mild symptoms in humans and other animals include red or reddish skin that is hot to the touch, general fatigue, and mild dizziness. An excess of UV...

, especially if one has fair skin. Recurring overexposure to ultraviolet radiation can cause some forms of skin cancer

Skin cancer

Skin neoplasms are skin growths with differing causes and varying degrees of malignancy. The three most common malignant skin cancers are basal cell cancer, squamous cell cancer, and melanoma, each of which is named after the type of skin cell from which it arises...

.

The sun's infrared radiation causes high air temperatures from the midday onwards, the highest temperatures taking place in the early afternoon. High temperatures can cause fatigue or in more serious cases heat exhaustion , hyperthermia

Hyperthermia

Hyperthermia is an elevated body temperature due to failed thermoregulation. Hyperthermia occurs when the body produces or absorbs more heat than it can dissipate...

 (sunstroke) and death

Death

Death is the permanent termination of the biological functions that sustain a living organism. Phenomena which commonly bring about death include old age, predation, malnutrition, disease, and accidents or trauma resulting in terminal injury....

.

Biological need for naps

Older, pre-teenage children are usually capable of napping, but acquire the ability to nap as teenagers as well.

The timing of sleep in humans depends upon a balance between homeostatic sleep propensity, the need for sleep as a function of the amount of time elapsed since the last adequate sleep episode, and circadian rhythm

Circadian rhythm

A circadian rhythm, popularly referred to as body clock, is an endogenously driven , roughly 24-hour cycle in biochemical, physiological, or behavioural processes. Circadian rhythms have been widely observed in plants, animals, fungi and cyanobacteria...

s which determine the ideal timing of a correctly structured and restorative sleep episode. The homeostatic pressure to sleep starts growing upon awakening. The circadian signal for wakefulness starts building in the (late) afternoon. As Harvard professor of sleep medicine

Sleep medicine

Sleep medicine is a medical specialty or subspecialty devoted to the diagnosis and therapy of sleep disturbances and disorders. From the middle of the 20th century, research has provided increasing knowledge and answered many questions about sleep-wake functioning. The rapidly evolving field has...

 Charles A. Czeisler notes, "The circadian system is set up in a beautiful way to override the homeostatic drive for sleep."

Thus, in many people, there is a dip when the drive for sleep has been building for hours and the drive for wakefulness has not yet started. This is, again quoting Czeisler, "a great time for a nap." The drive for wakefulness intensifies through the evening, making it difficult to get to sleep 2–3 hours before one's usual bedtime when the wake maintenance zone ends.

In some individuals, "postprandial dip

Postprandial dip

In medicine and specifically endocrinology, postprandial dip is a term used to refer to mild hypoglycemia occurring after ingestion of a heavy meal....

", a brief drop in blood glucose levels caused by the body's normal insulin

Insulin

Insulin is a hormone central to regulating carbohydrate and fat metabolism in the body. Insulin causes cells in the liver, muscle, and fat tissue to take up glucose from the blood, storing it as glycogen in the liver and muscle....

 response to a heavy meal, may produce drowsiness after the meal that can encourage a nap. However, the appearance of the dip is primarily circadian as it occurs also in the absence of the meal.

Siesta in other cultures

The concept of a midday nap is also prominent in other tropical or subtropical countries, where the afternoon heat dramatically reduces work productivity. The Washington Post of February 13, 2007 reports at length on studies in Greece

Greece

Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....

 that indicate that those who nap have less risk of heart attack.

An example of a siesta-like habit can be found in Serbia

Serbia

Serbia , officially the Republic of Serbia , is a landlocked country located at the crossroads of Central and Southeast Europe, covering the southern part of the Carpathian basin and the central part of the Balkans...

 and Slovenia

Slovenia

Slovenia , officially the Republic of Slovenia , is a country in Central and Southeastern Europe touching the Alps and bordering the Mediterranean. Slovenia borders Italy to the west, Croatia to the south and east, Hungary to the northeast, and Austria to the north, and also has a small portion of...

. Especially among older citizens, it is common to observe the so-called "house rule", requiring people to refrain from telephoning or visiting each other between 2 p.m. and 5 p.m., as people are supposed to be resting; especially since lunch in Serbia and Slovenia, eaten usually between 1 p.m. and 2 p.m., is the main dish of the day. In some southern German-speaking regions, the Mittagspause (:de:Mittagspause) or Mittagsruhe (:de:Mittagsruhe) is still customary; shops close, and children are expected to play quietly indoors.

In South Asia

South Asia

South Asia, also known as Southern Asia, is the southern region of the Asian continent, which comprises the sub-Himalayan countries and, for some authorities , also includes the adjoining countries to the west and the east...

, the idea of a post-lunch nap is common, and the idea of going to sleep after a light massage with mustard oil

Mustard oil

The term mustard oil is used for three different oils that are made from mustard seeds:*A fatty vegetable oil resulting from pressing the seeds,...

 to induce drowsiness was very popular before industrialization. It was also very popular to consume a light snack during this ritual; it was thought that this practice would make one a better person. In Bengal

Bengal

Bengal is a historical and geographical region in the northeast region of the Indian Subcontinent at the apex of the Bay of Bengal. Today, it is mainly divided between the sovereign land of People's Republic of Bangladesh and the Indian state of West Bengal, although some regions of the previous...

, the word which describes the concept is bhat-ghum, literally meaning "rice-sleep", a nap after lunch. In north India

India

India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

 a colloquial term sustānā (सुस्ताना), which literally means "taking small nap" (possibly of Persian origin), is used, although it does not necessarily mean siesta but it is used in same way. According ayurveda vamkukshi (nap in the afternoon) for 15-30 minutes after lunch is good for your health, it does not mean deep sleep but just lying down.

Afternoon sleep is also a common habit in China

People's Republic of China

China , officially the People's Republic of China , is the most populous country in the world, with over 1.3 billion citizens. Located in East Asia, the country covers approximately 9.6 million square kilometres...

 and Taiwan

Taiwan

Taiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...

 after the midday meal. This is called wujiao (午覺) in Chinese

Chinese language

The Chinese language is a language or language family consisting of varieties which are mutually intelligible to varying degrees. Originally the indigenous languages spoken by the Han Chinese in China, it forms one of the branches of Sino-Tibetan family of languages...

. Almost all schools in Mainland China

Mainland China

Mainland China, the Chinese mainland or simply the mainland, is a geopolitical term that refers to the area under the jurisdiction of the People's Republic of China . According to the Taipei-based Mainland Affairs Council, the term excludes the PRC Special Administrative Regions of Hong Kong and...

 and Taiwan

Taiwan

Taiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...

 have a half-hour nap period right after lunch. This is a time when all lights are out and one is not allowed to do anything other than rest or sleep.

Some Japanese

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

 offices have special rooms known as napping rooms for their workers to take a nap during lunch break or after overtime work.

In Islam, it is encouraged to take a nap before Dhuhr

Dhuhr

The dhuhr prayer is the prayer after midday Performed daily by practicing Muslims, it is the second of the five daily prayers...

(midday) , for those doing tahajjud

Tahajjud

Tahajjud , also known as the "night prayer" is a voluntary prayer, performed by followers of Islam. It is not one of the five obligatory prayers required of all Muslims, yet still, the Islamic prophet, Muhammad has been recorded as performing the tahajjud prayer regularly and encouraging his...

later in the night.

In the United States, the United Kingdom, and a growing number of other countries, a short sleep has been referred to as a "power nap

Power nap

A power nap is a short sleep which terminates before the occurrence of deep sleep or slow-wave sleep , intended to quickly revitalize the subject. The expression was coined by Cornell University social psychologist James Maas.-Characteristics:...

", a term coined by Cornell University social psychologist James Maas

James Maas

James Maas is an American social psychologist, professor at Cornell University, and Stephen H. Weiss Presidential Fellow. He is best known for his work in the field of sleep research, specifically the relationship between sleep and performance. He coined the term "power nap" and wrote the...

 and recognized by other research scientists such as Sara Mednick

Sara Mednick

Sara C. Mednick is a sleep researcher at the University of California, San Diego. Her research focuses on the relationship between napping and performance. She is the author of several papers and a mass market book, Take a Nap! Change Your Life....

 as well as in the popular press.

External links

• Why we could all do with a Siesta – An article about research results from the University of Manchester
  University of Manchester
  The University of Manchester is a public research university located in Manchester, United Kingdom. It is a "red brick" university and a member of the Russell Group of research-intensive British universities and the N8 Group...
  
  
• Indian ways of chilling peak summer noon hours