What is the Best Temperature for Sleeping?

Thermoregulation, a process allowing the body to maintain its core internal temperature, is a key factor affecting sleep. Since our body’s temperature decreases when we sleep, a cool room can facilitate the change and assist in helping us fall asleep.

Studies have shown if a room is too hot or too cold, it can disrupt our sleep. Hotter nights have been linked to more nights of insufficient sleep ¹ Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. See the source , and heat exposure is associated with more wakefulness ² Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. See the source and changes in sleep stages. Ultimately an ideal sleeping temperature depends on what’s comfortable for you, but many sleep experts recommend a bedroom temperature between 60 and 67 degrees Fahrenheit for most adults ³ Verified Source Cleveland Clinic A nonprofit academic medical center known for patient care, research and medical education. See the source .

In this article, we explain how temperature plays into our circadian rhythm and different ways to regulate your temperature to promote better sleep.

Understanding Circadian Rhythms and Body Temperature

Circadian rhythm, or our “internal body clock,” is responsible for maintaining our 24-hour sleep-wake cycle, and telling our body when to eat, sleep, and wake. This internal rhythm is primarily affected by light and darkness, explaining why we’re naturally active during the day and fall asleep easier at night.

Our body’s core temperature follows this cycle, rising and falling throughout the 24-hour period. Around the time we go to bed, our body’s temperature drops and continues to decrease during the night, reaching its lowest point in the early morning hours. It then begins to rise as we wake up.

The drop in temperature occurs when our skin’s blood vessels dilate. This adjusts blood flow to the skin and facilitates heat loss, making us cooler. A 2012 review describes how this heat loss through the skin is linked to the rapid onset of sleep ² Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. See the source and to melatonin secretion, the hormone responsible for making us sleepy.

How Room Temperature Affects Sleep

We can help our bodies lower their core temperature and promote sleep onset by making a room cooler; if a room is too hot, it can negatively affect our sleep stages and keep us awake. A cooler room supports the natural drop in core body temperature. However, a room that’s too chilly can also disrupt sleep, which is why it’s important to find a temperature in the middle of warm and cold.

“A good rule of thumb is to think of the ideal bedroom environment as being like a cave: cool, dark, quiet, and safe,” says Dr. Jessee Dietch, an assistant professor of psychology at Oregon State University. “The bottom line is that the environment, particularly the temperature, should be comfortable to you.”

Too Warm Temperatures and Sleep

Heat exposure is associated with more wakefulness and less deep and REM sleep ² Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. See the source , which can affect our overall quality of rest. Humid heat makes the effect worse.

Researchers in one study analyzed the relationship between nighttime temperature and human sleep loss ¹ Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. See the source . A total of 765,000 U.S. individuals were asked to report how many days over the past month they felt they did not get enough rest or sleep. The responses were then matched with the geolocation of each interview and compared against daily meteorological data, including temperature. The results showed that warmer-than-usual nights were associated with more self-reported nights of insufficient sleep ¹ Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. See the source .

Heat can be a concern for older adults, too. A 2023 study of older adults found they slept most efficiently when nighttime bedroom temperatures were between about 68 and 77 degrees Fahrenheit (20 to 25°C), with sleep efficiency dropping 5 to 10% as temperatures rose from 77 to 86°F ⁴ Verified Source Science of the Total Environment (Elsevier) A peer-reviewed environmental science journal. See the source . That’s a bit warmer than the range often recommended for younger adults, so older adults may want to experiment within a slightly warmer range.

Heat can also affect sleep stages including the deep, or slow-wave, sleep and rapid eye movement (REM) stages. Heat exposure is linked to less slow-wave and REM sleep, which can leave you feeling less refreshed.

Too Cold Temperatures and Sleep

Cooler temperatures tend to support sleep better than hot ones, since they help the body’s natural temperature drop at night.

In 2012, a Swedish study ⁵ Verified Source SLEEP (Oxford Academic) The peer-reviewed journal of the Sleep Research Society. See the source of 40 people with untreated obstructive sleep apnea found they slept about 30 minutes longer, slept more efficiently, and were more alert in the morning at about 61 degrees Fahrenheit (16°C) than at about 75 degrees (24°C). However, their sleep apnea was more severe at the cooler temperatures ⁵ Verified Source SLEEP (Oxford Academic) The peer-reviewed journal of the Sleep Research Society. See the source , so people with sleep apnea should follow their doctor’s treatment plan.

Cold can also disrupt sleep, especially if you aren’t covered well ² Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. See the source . Being too cold causes our muscles to contract in an effort to keep our bodies warm; this contraction prevents us from relaxing or feeling comfortable. When we’re unable to fully relax, our brains and our bodies have a difficult time drifting off to sleep.

Striking the Ideal Temperature Balance

Finding the right balance between a room that’s too hot or too cold is an important factor in getting a good night’s sleep. Generally speaking, many sleep experts suggest somewhere between 60 and 67 degrees Fahrenheit as a good sleeping temperature for most adults; however, you might want to play around with different bedroom temperatures to determine what specifically works for you. Setting your thermostat within this range allows you to stay cool enough to support the drop in your body’s internal temperature and warm enough to allow your muscles to relax.

Babies are different. Don’t try to keep a baby’s room cold. Instead, dress your baby in clothes suitable for the room temperature, avoid too many layers, and take off hats indoors so your baby doesn’t overheat ⁶ Verified Source Safe to Sleep, NICHD (NIH) The National Institutes of Health’s public education campaign on safe infant sleep. See the source .

Other Ways to Maintain a Comfortable Sleeping Temperature

Turning the thermostat down is one of the easiest ways to create a comfortable sleeping environment, but there are other ways to keep cool through the night.

• Use seasonally appropriate bedding: Airy bedding, like cotton, Tencel, and linen, promotes breathability and keeps you cool and dry through the night, especially in the summer. This type of bedding is often warm enough for winter temperatures too, making it great year-round in most climates.
• Wear light, breathable clothing: Like bedding, avoid clothing made of heat-retaining materials like polyester and satin when sleeping. Light, heat-wicking materials like cotton are ideal to keep you cool and comfortable all night.
• Use fans to keep air flowing: Fans are great at aiding in airflow, especially if you’re unable to control the room temperature from a thermostat.
• Take a warm shower or bath: The drop in body temperature after getting out of the warm water may help you feel sleepy, and the experience can help you relax.
• Reconsider your mattress: Some mattress types, like traditional memory foam, tend to retain heat and can leave hot sleepers sweaty. If your mattress is the cause of your overheating, try a gel mattress topper to put a cool-to-the-touch barrier between you and your bed, or upgrade to a more cooling mattress.

FAQs

Is it better to sleep in a cold or a warm room?

A cooler environment tends to support better sleep. Our body’s core temperature drops when we sleep as blood vessels in the skin widen and release heat, a process linked to melatonin secretion. Cooler rooms facilitate this change and can help us to fall asleep quicker. However, if the room is too cold, it can wake you up or keep you awake.

On the other hand, hot temperatures inhibit the drop in body temperature associated with sleep and can prevent us from dozing off. Warmer temperatures are linked to less deep sleep and REM sleep, stages that help us feel rested and refreshed. Furthermore, sleeping in a room that’s too hot is likely to produce night sweats, preventing us from feeling comfortable and getting good quality sleep.

What is the ideal room temperature for sleeping?

Typically, somewhere between 60 and 67 degrees Fahrenheit is an ideal temperature for most people ³ Verified Source Cleveland Clinic A nonprofit academic medical center known for patient care, research and medical education. See the source because it’s not too hot or too cold. We suggest starting somewhere in this range and adjusting as needed.

How cold is too cold for sleeping?

A temperature that’s “too cold” will vary from person to person. There’s no set cutoff, but if you’re shivering or can’t relax because you’re cold, your room is probably too cold for good sleep. Raise the bedroom temperature a couple of degrees and gauge how you feel. If you’re unable to control the bedroom temperature, you might add an extra blanket or thermal sleepwear.

Does a warm shower at night help or prevent sleep?

Our internal temperature naturally decreases at night and signals to our body it’s time to sleep. After a warm shower or bath, the drop in your body’s core temperature can promote this change and boost drowsiness. Furthermore, a warm shower prior to getting into bed can help you relax and unwind, preparing your mind and body for rest.

How can I stay cool at night without adjusting the room temperature?

If you want to save money on your energy bill, there are other effective ways to keep cool. A breathable mattress and bedding can encourage airflow to help keep you dry and cool through the night. Likewise, airy and light clothing will also aid in keeping you comfortable by wicking away moisture and heat.

Fans are great at increasing airflow and cooling a room down. They can help you stay dry and cool the surface of your skin. Additionally, opening a window can also improve airflow to curb night sweats.

Conclusion

A room’s temperature can facilitate or inhibit the natural cooling of our body’s core when we sleep. A room that’s too hot can keep us awake, disrupt our sleep stages, and cause night sweats, while one too cold will prevent us from relaxing.

While there’s no one magic number that universally works for everyone, many sleep experts recommend a cooler temperature for most adults, somewhere between 60 and 67 degrees Fahrenheit.

What feels too cold or hot will vary from each person, so testing out different temperatures in the suggested range is key to finding one most comfortable to you. An environment conducive to promoting quality sleep will ensure a restful night.