Ever wonder how a blanket can keep you warm?

Under Blankets are hot for a scientific reason

Even if you bake in a vacuum, you may still be covered. Fortunately, science can explain why.

Each of us has a favorite sleeping position—whether it's the fetal curl, the stretched starfish, the craving stretch, or the logarithmic position (these are the best for your health). Most of us prefer feather or foam pillows, soft or firm mattresses, cotton or silk sheets. But a common sleep habit that most people share is our tendency to sleep under the covers.

Things you may interest: Are Electric Blankets Safe? Precautions and Safety Tips

While bedding was once a luxury for the powerful and privileged, such as royalty and wealthy businessmen, sleeping under a blanket is now commonplace. Even if you bake bread in a vacuum, you can still be full. How does it work?

As always, science provides answers to our most puzzling questions. For one thing, your body's core temperature drops before and during sleep, so you need a blanket for a simple, practical reason: to keep you from shaking.

This nighttime cooling doesn't just keep you comfortable during naps—it's actually an important part of regulating your circadian rhythm, which determines when your body is ready to go to sleep and when it's ready to wake up. It starts about an hour before you lie down on the quilt and continues to decrease as you sleep, eventually reaching a degree or two below your average body temperature. But once you enter the REM (rapid eye movement) sleep cycle, your body loses its ability to regulate body temperature. Your blanket will keep you warm - even on summer nights.

There is also a behavioral factor in sleeping with bedding. To be honest, we are used to using blankets from birth.

"Blankets create a 'microclimate' around the skin, which is usually warmer than the surrounding area," says Dr. Michael Graner, director of the Sleep and Health Research Program at the University of Arizona in Tucson. "It captures the heat emitted during the night and keeps the body warm. And since most people sleep under a blanket, the physical sensation associated with sleep in the blanket itself is ready to fall asleep. It can actually trigger the sleep response.

Things you may interest: Woven Photo Blanket

Research suggests that weighted blankets may be especially beneficial for people with insomnia and anxiety. A 2015 study of healthy people with chronic insomnia, published in the Journal of Sleep Medicine and Disease, found that those who slept under a weighted blanket had more restful sleep. A 2020 review of studies published in the American Journal of Occupational Therapy suggests that people with anxiety disorders may also benefit from using a weighted blanket to sleep.

Why? Not only do blankets make them feel safe and secure, they also make them more comfortable.

"The perfect blanket is warm enough to be comfortable, yet breathable enough not to collect moisture and sweat," says Graner. "It should be soft enough to keep you out of the way, but firm enough that you can feel it."

When choosing a weighted blanket, remember: what matters is the actual weight of the blanket. It shouldn't be too light or heavy, the researchers noted, and the weight needs to be evenly distributed throughout the fabric.

Complaining or not, Grandner adds: "A soft, comfy blanket can relax and help you fall asleep."

Reason enough to strike tonight.

Things you may interest: What is a quilt cover? |Duvet vs Quilt

Cloudy days are very comfortable.

late July. New York City. In a bedroom on the top floor of a four-story building, I installed an air conditioner with several thousand BTUs. I hardly know what a BTU is. The temperature reached over 90 degrees Fahrenheit that day, and the humidity was slightly below the actual water level. The weak air conditioner had trouble keeping the room cool when I was trying to fall asleep a few feet away. However, I can't sleep without a blanket. In this case, it was the bare edge of my lightest sheet that touched the smallest part of my torso.

Why is this obsessive cover-up even minimal sleep?

A Red Cross nurse changing sheets on a patient's bed in 1917.

A Red Cross nurse changing sheets on a patient's bed in 1917. National Archives/20802254

Blankets are common for people to sleep in, but not universal, at least in modern times. But in the past, the cost of weaving large sheets made blankets unaffordable for most people. Linen from Egypt around 3500 BC. From woolen sheets in the Roman Empire to cotton in medieval Europe, quilts were for the rich.

GASTRO OBSCURA BOOK

Taste the world!

Explore the history, culture and places of the culinary world.

Order now

Gastro Obscura Book

VIDEO FROM ATLAS OBSCURA

00:04 / 05:17

In early modern Europe after the Middle Ages, production had increased to the point where more middle-class citizens could afford bedding, although it wasn't easy. “At the time, the bed was the most expensive item in a house in all of Western Europe,” says Virginia Tech historian Roger Ekirch, who has written extensively on sleep. "It's the first major project a newlywed couple would invest in if they had spare cash." Sheets and sheets can account for about a third of the total value of an entire home, which explains why sheets are so common. in the will.

Things you may interest: How to Fold a Blanket for Kids

A depiction of a 15th century bed.

A depiction of a 15th century bed. Public area

In addition to blankets and sheets, other sources of heat are common at night, mainly from several people sharing a bed, or often from livestock.

Today, there is very little anthropological writing on the subject of garbage worldwide. Foremost is a 2002 paper by Emory University's Carol Worthman and Melissa Melby, who looked at sleep arrangements in different parts of the world. "It is encouraging to acknowledge that there is little anthropological work on the topic of sleep: it is an important area of ​​human behavior, accounting for one-third of everyday life, but is dominated by fields devoted to the study of human existence as a whole Dominated, they wrote. In a scientific paper, this was interpreted as anger.

The paper surveyed some foraging and non-foraging populations living in hot climates near the equator and found that only nomadic foragers usually sleep without duvets. All others use some form of mulch, whether plant matter or woven cloth, even in the two tropical climates of Central Africa and Papua New Guinea. Mats are more common than sheets or blankets; basically, no one just sleeps on the floor.

As another example of the benefits of blankets, there is also plenty of research on the calming effects of weighted blankets, which can weigh up to 30 pounds. Studies have shown that they can suppress anxiety and even be used to treat autism.

Linen sheets from the early 1800s.

Linen sheets from the early 1800s. Public area

"The need for a blanket has two parts," says Dr. Alice Hoagland is director of the Insomnia Clinic at Unity Sleep Disorders Center in Rochester, New York. "There's a behavioral component and a physiological component." The latter is a bit clearer, so let's look at that first.

Core body temperature begins to drop about 60 to 90 minutes before normal bedtime. There is a physiological explanation for this: when the body is heated, we feel more awake. Conversely, we tend to feel more sleepy when the body cools down. Lower body temperature is associated with an increase in melatonin, a hormone that triggers drowsiness. A group of doctors tested this by putting people in tights -- they look like bicycling gear -- to lower their body temperature by a degree or two Fahrenheit to see if they would sleep better. you did it.

Things you may interest: What is ceiling insulation?

However, your body's ability to regulate its own heat is more complex than at night. Say you sleep eight hours a night. During the first four hours, plus about an hour before bed, your body temperature will drop slightly from about 38 degrees Fahrenheit to about 36 to 37 degrees. But the next four hours are marked by REM (rapid eye movement) sleep, a phenomenon that occurs in most of our dreams, and various physical changes.

One of these physical changes is the inability to regulate body temperature. "They almost recovered to more, which is my word, form of thermoregulation in reptiles," Hoagland said. She said "reptiles" because reptiles cannot regulate their own body temperature like we mammals; reptiles must regulate their body temperature by external means other than sweating and shaking, such as B. walking in the sun or shade. During these brief REM sleeps, we all become lizards.

Sheets dry in the sun.

Sheets dry in the sun. LINDA/CC BY-ND 2.0

Even in perpetually hot climates, temperatures drop at night, which happens to be the coldest time, and our bodies are in a state of collapse, unable to adapt. (Nights are coldest after sunrise, which directly contradicts the adage.) So, like lizards, we must have external means of regulating our body temperature. When it's still hot at 10pm, you might think you don't need a blanket, but it's colder at 4am, can't you shiver? you may need it. So we probably know from past experience that in the future we'll be thankful that we have a blanket, so we'll force ourselves to use one (or at least have one nearby) while we sleep.

However, it is much more than that. Another weird thing that happens during REM sleep is that our bodies drastically reduce levels of serotonin, the neurotransmitter most associated with rest, well-being and feelings of well-being. Do you know what is associated with higher serotonin levels? home page. Various studies have shown that sleeping with a weighted blanket increases serotonin production in the brain. Blankets, on the other hand, satisfy the REM demands that our brains generate.

A bed with a bassinet.

A bed with a bassinet. CHRISTOPHE.FINOT/ CC BY-SA 3.0

Another factor that might explain our need for blankets is what Hoagland calls "pure conditioning." "You probably always go to bed with a blanket," she said. "So it's a version of a transitional object in the Pavlovian way." Basically, our parents always put us in blankets to sleep in -- babies have slightly lower thermoregulation than adults, which means they're prone to colds , which means they're fine -- which means adults put blankets over them -- so stick to the sheets or blankets that accompany it to sleep. It's not that Pavlov's dog drools when the bell rings, it's that we get sleepy when we pull on the sheets.

If you google this question, you'll end up with many theories about blankets that simulate the warm, enclosed feeling we feel in the womb. The blanket could have a theoretical element of protection or safety, which could be another adaptation, but Hoagland thinks it's unlikely compared to the womb. "I highly doubt that anyone thinks it's what it feels like in the womb," she said. "I think it's very far-fetched."

Another possible reason is that the blanket is soft and feels good in the hand. I can't find any research on whether people like blankets because they're soft and feel good, so that's probably a big open question.

You've just read :Ever wonder how a blanket can keep you warm?