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What is lüften and should you be doing it for better sleep?

What is lüften and should you be doing it for better sleep?
Posted at 7:40 AM, Mar 14, 2024

Did you get enough sleep last night?

If you’re like most Americans, the answer is no. The average American gets much less than the recommended seven to eight hours of sleep each night. Poor sleep has been linked to health problems including Type 2 diabetes, high blood pressure, depression and more.

There is a trending sleep aid gaining buzz that might help you catch some more z’s — and it costs nothing at all and has no worrying side effects. It’s also not technically new, at least if you live in Austria.

We’re talking about stoßlüften, a German word that means “shock ventilation.” But don’t panic: Although it might sound intense, it’s a soothing practice that parents in Austria even use with babies and young children.

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What Is Lüften?

Known in Germany and Austria as lüften for short, this is a sleep practice in which you decrease the temperature in the bedroom. Lüften translates to “the air,” but this historic practice stems back generations, many decades before modern HVAC systems. (And air conditioning continues to be rare in Austria to this day.)

Therefore, lüften is not when you lower the temperature of your air conditioner, but when you open the windows so the cool night breeze can enter.

Lüften is so important in Germany that the practice is even posed as a requirement in many leases. This is because German homes are famously airtight and don’t have the ventilation systems commonly found in American homes. This can cause mold to grow, which is why many landlords in Germany require tenants to air out their home every day.

But lüften isn’t just important for releasing moist air and preventing mold. It can also help promote better sleep.

woman sleeping in bed

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How Does Lüften Promote Better Sleep?

Studies have shown that cold air leads to deeper and more restorative sleep. A study published in Frontiers of Neuroscience found that people sleep better in cold temperatures, getting 30 more minutes of REM sleep than people who sleep in warmer temperatures.

REM sleep is crucial for our mental health and our cognitive abilities, as it’s during this phase of sleep that our brain replenishes, restores and recovers. REM sleep is also essential for our immunity, meaning that we can actually risk illness if we don’t get enough quality rest.

REM sleep is especially important for babies. Babies spend more time in REM sleep than adults do, and without this crucial sleep phase, babies can suffer from a lack of neuronal plasticity and synapse formation, even in adulthood.

A baby in a stroller in the snow

Why Do Some Parents Let Their Baby Nap Outside In Cold Weather?

Parents who want to prioritize deep and restful sleep for their infants opt for lüften sleep practices, even in countries outside of Austria.

In many Nordic countries, it is common for parents to have their little ones nap outside, even in frigid temps. A study revealed that parents living in Oulu, Finland have been known to let their babies nap outdoors in very cold temperatures. The same study also revealed that this is a cultural practice that is both unremarkable and encouraged. 

“Allowing children to sleep outdoors in the winter was considered a common practice and was taken for granted. It usually began when the child was 2-weeks-old, and was carried out once a day,” the researchers stated. “Children took longer naps outdoors compared with naps taken indoors. Outdoor temperatures ranged between -27 and +5 degrees Celsius [16 to 41 degrees Fahrenheit]. Parents’ experiences were mainly positive and most parents had not faced potentially dangerous situations.”

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Is Sleeping In Very Cold Temperatures Safe?

It is important to note that such cold temperatures aren’t recommended by experts, especially if you are not accustomed to this Nordic practice.

But you and your family can safely benefit from lowering the temp when you sleep. While you don’t want the room to be too cold, a room that is too hot can also be a major concern.

Pediatricians say that overheating can be a risk factor for SIDS. They recommend having infants sleep in temps between68 to 72 degrees Fahrenheit. Research has also shown that sleeping with a fan running can decrease an infant’s risk of SIDs by 72%. This suggests that getting cool air circulating can help promote safer sleep. 

For adults, sleep experts recommend anywhere from 60 to 67 degrees Fahrenheit as the ideal bedroom temperature for deep, comfortable sleep.

boy sleeping with teddy bear

What Does Temperature Have To Do With Better Sleep?

So, now we know that cooler temps have been proven to promote better sleep… but the question remains: Why?

It might come down to melatonin. Melatonin is produced in the pineal gland of your brain. This hormone controls our sleep-wake cycles and it can also impact our body’s core temperature. As melatonin goes up, our core temperature goes down. This means that turning down the thermostat, switching on a fan, or opening a window before bed might help to mimic the role of this crucial sleep hormone.

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Melatonin initiates a cascade of other sleep processes within in the body, so lowering the temp could encourage your entire body to begin switching into rest mode.

If you live in a warm climate and can’t engage in traditional lüften by inviting in the cold night air, you can still get a cooling boost before bed. Dr. Austin Perlmutter, who led the sleep temperature research in the above study, says you can try evaporative cooling of the body instead.

woman holding hot tea

Dr. Perlmutter told CBS News an easy way to cool your body. “Taking a hot bath, taking a hot shower, and when you get out of that hot bath or shower, you’re actually going to increase your body’s cooling, because you’re sending all of that blood to your skin.”

Hot drinks can also help initiate evaporative cooling within the body. Yes, it sounds counterintuitive, but this is another centuries-old practice that science supports.

“If you drink a hot drink, it does result in a lower amount of heat stored inside your body, provided the additional sweat that’s produced when you drink the hot drink can evaporate,” thermal researcher Ollie Jay told Smithsonian Magazine.

No wonder drinking hot tea on hot days is a common practice in countries like India.

Luckily for us, many of us have air conditioning, fans, high-tech wicking fabrics and cooling gel pillows to help us sleep as cool and comfortably as possible. But don’t discount the simple pleasure of merely cracking a window open or perhaps taking a walk in the night air before you go to bed.

Turns out our grandmothers were right: Fresh air is good for us!

What is lüften and should you be doing it for better sleep? originally appeared on