Sleeping in a cool, dark space helps support natural sleep cycles. (Getty Images)
If you find yourself tossing and turning at night more than usual, your room temperature may be to blame. As it happens, the mechanisms in our bodies that regulate sleep are widely affected by temperature, so any fluctuations — hot or cold — can make sleep more challenging. That said, experts agree that sleeping in a dark, cool environment lends itself to high-quality sleep. According to the doctors at UT Health San Antonio, the best temperature for sleep is somewhere between 60 and 67 degrees Fahrenheit, although the exact number can vary slightly from person to person.
And as one 2023 study demonstrates, for adults who typically sleep with room temperatures between 68 and 77 degrees Fahrenheit, increasing the temperature to between 77 and 86 degrees Fahrenheit significantly impacted sleep quantity and quality by as much as 10%. "Temperature plays a significant role in how smoothly you transition through different sleep stages," says Chelsea Perry, owner of Sleep Solutions in Westborough, Mass. "If your environment is too warm or too cold, it can disrupt this process, causing you to wake up or shift into lighter sleep stages."
While we can't control internal mechanisms that affect our body temperature, like the circadian rhythm, we can adjust external factors such as room temperature, bedding and fabric types to improve our sleep quality.
Here's what you need to know about the ideal room temperature for sleep.
As a 2012 study explains, sleep and body temperature are intricately linked and impact each other. All humans operate on a 24-hour circadian cycle that affects everything in our body, from digestion to metabolism to sleeping.
Part of that 24-hour cycle is our core body temperature, which cycles just like our sleep-wake cycle. Our body temperature decreases as the body primes for sleep and increases when it's time to wake up. The deepest stages of sleep coincide with the times that body temperature is the lowest.
"Hormones released in the brain, such as melatonin, help trigger this temperature decrease," says Dr. Abhay Sharma, assistant professor and director of the Division of Interventional Sleep Surgery at the USF Health Morsani College of Medicine in partnership with Tampa General Hospital. "The temperature continues to drop until two hours prior to waking up. Once our body temperature begins to rise, it naturally signals the brain to wake up."
Sharma explains that the drop in body temperature is an "evolutionarily built-in" mechanism that prepares the body for sleep and occurs in all mammals. This drop is driven by thermoregulation in the body, such as increased blood flow to the skin and the dilation of blood vessels to facilitate cooling.
"Skin temperature rises a bit, pulling blood from your core and then cooling it to promote deeper, more restful sleep," notes Mark S. Aloia, PhD, head of Sleep and Behavioral Sciences at Sleep Number and associate professor at National Jewish Health.
Because your body is already experiencing internal temperature changes, other external factors, like the room temperature or what you're wearing, can disturb your sleep as you move through the different sleep stages.
A room that's too hot can make it difficult for your body to reach the ideal cool-temperature stage to fall asleep and can also jolt the body out of deep sleep stages.
"Scientifically, our bodies need to be cool for the best possible sleep," states Aloia. "If a room is too hot, you could have more trouble falling and staying asleep because the heat will raise your core body temperature."
Research suggests that in typical sleeping situations when someone is wearing pajamas and using blankets, a too-hot environment is more disruptive than a room that's too cold.
Older adults and young infants may be especially affected because they have more trouble regulating their internal body temperatures. Additionally, anyone going through hormonal changes, such as with perimenopause and menopause, may also have trouble staying cool, so a room that's too hot can further impact sleep.
Heat by itself is detrimental to sleep quality, but the research also points out that humidity is particularly disruptive. So if your room is hot and humid, you may be in for a poor night's sleep.
According to Aloia, even though slightly colder temperatures are necessary for the body to sleep, a room that is too cold can also interrupt sleep.
Specifically, a too-cold environment can make it difficult to get comfortable, fall asleep and stay asleep.
Aging can also exacerbate the impact of a too-cold room on sleep. "Older adults might need slightly warmer rooms as we may have less of an ability to conserve heat as we age," says Shelby Harris, a clinical psychologist board-certified in behavioral sleep medicine (BSM) by the American Academy of Sleep Medicine and director of Sleep Health at Sleepopolis.
The key to a better night's sleep is experimenting within the recommended temperature range to find what works best.
"Not everyone has the same ideal sleeping temperature because personal preferences and individual body differences can vary," says Perry. "The key is to find a temperature that helps you feel cozy and allows your body to maintain its natural cooling process for a good night's sleep."
Aloia notes that temperature preferences can fluctuate in different stages of life and from person to person. Some other things that can impact internal body temperature and disturb sleep include:
Lifestyle changes
Hormones
Certain medical conditions, such as thyroid disorders
Medications
Vigorous exercise close to bedtime
Menopause and perimenopause
Caffeine
Sharma adds that infants, especially newborns, don't have the same temperature regulation capabilities as adults, so they may have more difficulty in too-hot or too-cold environments.
According to the American Academy of Pediatrics, it's important to watch for signs of overheating in babies, like flushed or hot skin. Ensure that babies are dressed appropriately for the room's temperature and avoid adding more than one extra layer compared with what an adult would wear. Overheating is a known risk factor for sudden infant death syndrome (SIDS).
In addition to finding the right room temperature, here are some general tips to help set the best sleeping environment:
Use a cooling fan
Set a programmable thermostat that can automatically lower and raise the temperature
Try cooling sheets and blankets during hot weather months
Switch to an electric blanket to stay warm in the cold
Open windows on both sides of a room or house to create airflow
Spend time in a public place with air conditioning during the day to help prevent overheating
Take a cool shower or bath before bed
Here are some additional expert tips for creating the best room temperature for sleeping:
According to Perry, even if your room feels too hot or too cold as you get ready for bed, it's probably a good idea to refrain from adjusting the temperature too much.
"It's generally best to keep the room temperature consistent throughout the night," she says. "Maintaining a stable temperature helps your body stay restful, supporting a continuous and deep sleep cycle."
If you can, program your sleeping area to stay at one temperature for the duration of your sleep. "I personally have my thermostat set to 65," Perry says.
The right type of fabric for your bedding can make a big difference in your body temperature for sleep. "In my view, when it comes to cooling, nothing is better than high-performance polyester," notes Derek Hales, founder and editor in chief of NapLab.com.
He recommends the brands Bedgear and Sheex for high-performance polyester sheets that are ultra-lightweight, highly breathable and moisture-wicking. "I have three sets of sheets in my personal rotation; one is Bedgear, and one is Sheex," he adds.
For those who prefer a natural fiber, "It doesn't get better than 100% cotton," Hales says. Stick to a 250-thread count for maximum breathability, durability and softness. "Higher thread counts create worse cooling, as the fabrics just can't breathe as well, so sticking around 250 is the ideal thread count when it comes to cooling," he adds.
Aloia says it's common for couples to struggle with temperature disruptions from a partner at night, with many often reporting that their partner sleeps too hot or too cold.
To help decrease these issues, you can experiment with sleeping apart or look at an adjustable bed that allows for dual temperature settings for each partner to choose their ideal bed temperature.
A cool room enhances sleep by aligning with the body’s natural circadian rhythm. As your body prepares for sleep, its temperature naturally lowers, and a cooler environment supports this process. Conversely, a rise in body temperature (which can be affected by a room's ambient temperature) signals the body to wake up. Therefore, maintaining a cool room can help promote better sleep.
Most adults sleep best between 60 and 70 degrees Fahrenheit, although some life stages, such as a woman going through menopause, may slightly change the ideal temperature. Older adults and infants also have more difficulty regulating their own body temperature, which can affect the ideal ambient temperature of a room for sleep.
The deepest stages of sleep align with the times when body temperature is the lowest. Increases in body temperature signal the brain and body that it's time to wake up. However, too-cold temperatures can also make falling and staying asleep difficult, especially if you don't have clothing or sufficient bedding to keep you warm.
If you have a thermostat, set or program your room temperature to somewhere between 60 and 70 degrees Fahrenheit before going to bed (between 65 and 68 degrees Fahrenheit is a popular range for the doctors and experts we interviewed for this article). If you don't have air conditioning, try facilitating a cooler room temperature by using box or overhead fans, blackout shades or curtains and wearing lightweight clothing to bed. Products like heating and cooling blankets and smart mattresses can also help adjust body temperature for more restful sleep.
Difficulty falling or staying asleep, waking up sweating or shivering, consistently adding or removing bedding during the night or needing to adjust a fan or add pajama layers could all be signs that you're not sleeping in an ideal temperature environment, says Sharma.
Abhay Sharma, MD, assistant professor and director of the Division of Interventional Sleep Surgery at the USF Health Morsani College of Medicine in partnership with Tampa General Hospital
Mark S. Aloia, PhD, head of Sleep and Behavioral Sciences, Sleep Number; associate professor, National Jewish Health, Denver
Derek Hales, founder and editor in chief of NapLab.com in Scottsdale, Ariz.
Shelby Harris, PsyD, clinical psychologist board-certified in behavioral sleep medicine (BSM) by the American Academy of Sleep Medicine; director of Sleep Health at Sleepopolis, practicing in New York
Chelsea Perry, DMD, owner of Sleep Solutions in Westborough, Mass.
