What Is the Best Temperature for Sleep?

Key Takeaways

• Temperature has a direct correlation with our circadian rhythm. 
• Studies have shown older adults sleep better in environments between 68°F–77°F (20°C–25°C) ^[1] Baniassadi, A., et al. Nighttime Ambient Temperature and Sleep in Community-Dwelling Older Adults. Science of the Total Environment. Nov. 15, 2023. Found on the internet at https://www.sciencedirect.com/science/article/abs/pii/S0048969723042468?via%3 . 
• Sleeping temperature impacts stages of sleep: rapid eye movement (REM), non-rapid eye movement (NREM), and slow wave sleep (SWS).
• Hot and humid sleeping environments can result in insomnia due to increased core temperature.
• Working out two to three hours before bedtime can help you relax.
• Taking a warm bath or shower one to two hours before bed has been shown to decrease the time it takes to fall asleep.

Sleep is essential for our overall health and well-being. Sleep deprivation, or not getting enough sleep, has been linked to many health concerns, including heart disease and diabetes. That said, only 35.5% of American adults have reported getting enough sleep ^[1] Baniassadi, A., et al. Nighttime Ambient Temperature and Sleep in Community-Dwelling Older Adults. Science of the Total Environment. Nov. 15, 2023. Found on the internet at https://www.sciencedirect.com/science/article/abs/pii/S0048969723042468?via%3 . Getting enough nightly rest often depends on establishing and maintaining good sleep hygiene. 

Tips for better sleep include keeping your bedroom dark, quiet, and at a comfortable temperature ^[2] Centers for Disease Control and Prevention. Tips for Better Sleep. Reviewed Sept. 13, 2022. Found on the internet at https://www.cdc.gov/sleep/about_sleep/sleep_hygiene.html . Keeping temperatures cool can impact the body’s natural temperature decrease during sleep ^[3] Szymusiak, R. Body temperature and sleep. Handbook of Clinical Neurology. 2018. Found on the internet at https://pubmed.ncbi.nlm.nih.gov/30454599/ . 

How does temperature affect sleep?

Temperature and sleep work together to optimize our rest. Studies show that changes in body temperature impact areas of the brain responsible for the onset of sleep ^[4] Gilbert, S, et al. Thermoregulation as a sleep signalling system. Sleep Medicine Reviews. 2004. Found on the internet at https://www.sciencedirect.com/science/article/abs/pii/S1087079203000236?via%3Dihub . In the anatomy of sleep, the hypothalamus affects our sleep-wake cycles by processing the amount of light around us ^[5] National Institute of Neurological Disorders and Stroke. Brain Basics: Understanding Sleep. July 19, 2023. Found on the internet at https://www.ninds.nih.gov/health-information/public-education/brain-basics/brain-basics-understanding-sleep . This light-dark cycle closely corresponds to the 24-hour sleep-wake cycle and is active even in those with impaired vision. Other areas of the brain that play a role in our sleep include the brain stem, thalamus, and pineal gland.

Thermoregulation is the process that maintains our core body temperature between 97.7°F–99.5°F (36.5°C–37.5°C) ^[6] Osilla, E, et al. Physiology, Temperature Regulation. StatPearls [Internet]. July 30, 2023. Found on the internet at https://www.ncbi.nlm.nih.gov/books/NBK507838/ . Our circadian rhythm and sleep regulation are directly related to thermoregulation ^[7] Okamoto-Mizuno, K, et al. Effects of thermal environment on sleep and circadian rhythm. Journal of Physiological Anthropology. 2012. Found on the internet at https://jphysiolanthropol.biomedcentral.com/articles/10.1186/1880-6805-31-14 . Warmer room temperatures impact sleep by decreasing the amount of rapid eye movement (REM) and slow wave sleep (SWS), thereby decreasing the quality of sleep. 

Preferences for bedroom temperatures can vary greatly from person to person. Some may prefer a colder environment so they can cuddle up with warm blankets or a partner, while others prefer a warmer environment and sleep with minimal clothing and bedding. Sleep clothing or bedding can be added or reduced depending on the room temperature to achieve this optimal temperature. 

Stephanie Dixon, MSN, FNP-C, a health care provider in North Carolina, said, “Managing the sleeping environment’s temperature is crucial for good quality sleep, and small adjustments can have a large impact on sleep quality and overall well-being.”

The ideal sleeping temperature

Younger adults may sleep well at cooler temperatures ( 60°F–68°F), but a recent study of older adults concluded that optimal sleep quality was achieved when temperatures were between 20°C–25°C (68–77°F) ^[8] Baniassadi, A, et al. Nighttime ambient temperature and sleep in community-dwelling older adults. Science of The Total Environment. Nov. 15, 2023. Found on the internet at https://www.sciencedirect.com/science/article/abs/pii/S0048969723042468?via%3D . Researchers noted a 5–10% decrease in sleep quality when the temperature increased from 25°C to 30°C (77°F to 86°F). Key results from the study show that maintaining the optimum temperature impacts the duration and quality of sleep. Also, people who slept within the ideal temperature experienced less restlessness during sleep. 

Seasonal weather changes can also impact sleep. For instance, a study concluded that increased outdoor temperatures negatively impact our health, causing fatigue and poor sleep quality ^[9] Fujii, H, et al. Fatigue and sleep under large summer temperature differences. Environmental Research. April 2015. Found on the internet at https://www.sciencedirect.com/science/article/abs/pii/S001393511500033X?via%3Dihub . 

What happens if it’s too warm?

A 2020 study of 3.75 million nights of sleep demonstrated that people who slept with higher bedroom temperatures experienced poorer sleep and higher wakefulness.

Heat can impact the onset of sleep and increase sweating as the body tries to lower core temperature to the optimal range for sleep. If the environment is also humid, the amount of sweating can dampen clothing and bedding, decreasing their insulation and leading to lower core temperature ^[7] Okamoto-Mizuno, K, et al. Effects of thermal environment on sleep and circadian rhythm. Journal of Physiological Anthropology. 2012. Found on the internet at https://jphysiolanthropol.biomedcentral.com/articles/10.1186/1880-6805-31-14 . 

Core temperature continues to decrease during the rapid eye movement (REM) stage of sleep, and sweating was noted to decrease as the body progressed to the next stages of sleep. That said, if the ambient and core temperatures remain elevated, a decrease in the non-rapid eye movement (NREM) and slow wave sleep (SWS) stages occurs, resulting in poor-quality sleep. 

Does ideal sleep temperature change with age?

Older adults frequently experience poor sleep, which affects their overall health and well-being ^[8] Baniassadi, A, et al. Nighttime ambient temperature and sleep in community-dwelling older adults. Science of The Total Environment. Nov. 15, 2023. Found on the internet at https://www.sciencedirect.com/science/article/abs/pii/S0048969723042468?via%3D . 

Poor sleep can lessen cognitive and physical function, mood, productivity, and diabetes management. Room temperature has been associated with quality of sleep in older adults, with the best results occurring between 68°F–77°F (20°C–25°C) ^[8] Baniassadi, A, et al. Nighttime ambient temperature and sleep in community-dwelling older adults. Science of The Total Environment. Nov. 15, 2023. Found on the internet at https://www.sciencedirect.com/science/article/abs/pii/S0048969723042468?via%3D . Lack of sleep in older adults has also been associated with early onset of dementia, cardiovascular disease, and osteoporosis. 

How to optimize your bedroom temperature

Now that we have explained the importance of sleeping temperatures, let’s explore what you can do to improve your sleeping environment. You can achieve a cooler sleep environment through many different methods. 

In the cooler months, you may find it helpful to open your bedroom window to supplement the cooling from your HVAC system. Lower your thermostat to your optimal sleeping temperature an hour or so before bedtime. Consider the current state of your mattress and whether it’s time for a replacement. Some of the newer, best mattresses have cooling features built-in and can help you achieve your optimal sleep temperature. And some of the best cooling mattresses are specifically designed to keep you cool at night.

Many sources for sleep hygiene recommend avoiding large meals, caffeine, and alcohol in the hours leading up to sleep. Exercise, such as taking a walk or other activities, can help you sleep; just be sure you complete these two to three hours before bed. In addition, a 2019 study found that nightly warm showering or bathing one to two hours before bed can improve the onset of sleep and overall sleep quality ^[12] Haghayegh, S, et al. Before-bedtime passive body heating by warm shower or bath to improve sleep: A systematic review and meta-analysis. Sleep Medicine Reviews. August 2019. Found on the internet at https://www.sciencedirect.com/science/article/abs/p . 

Bottom line

Maintaining an optimal sleep environment is crucial to consistently achieving good sleep quality. While temperature preferences will vary from one person to another, the consensus for optimal temperature is between 68°F–77°F for older adults and as low as 60°F for the younger population. 

Temperature directly relates to our circadian rhythm and sleep stages. Higher core temperatures impact REM, NREM, and SWS and can affect overall sleep quality. Good sleep hygiene and maintaining the optimal sleep environment, including ideal sleep temperature, can help improve sleep and reduce the complications caused by sleep deprivation. 

Have questions about this article? Email us at reviewsteam@ncoa.org.

Sources

1. United Health Foundation: America’s Health Rankings. Insufficient Sleep Trends by Age. Found on the internet at https://www.americashealthrankings.org/explore/measures/sleep?population=sleep_65
2. Centers for Disease Control and Prevention. Tips for Better Sleep. Reviewed Sept. 13, 2022. Found on the internet at https://www.cdc.gov/sleep/about_sleep/sleep_hygiene.html
3. Szymusiak, R. Body temperature and sleep. Handbook of Clinical Neurology. 2018. Found on the internet at https://pubmed.ncbi.nlm.nih.gov/30454599/
4. Gilbert, S., et al. Thermoregulation as a Sleep Signaling System. Sleep Medicine Reviews. April 2004. Found on the internet at https://www.sciencedirect.com/science/article/abs/pii/S1087079203000236?via%3Dihub
5. National Institute of Neurological Disorders and Stroke. Brain Basics: Understanding Sleep. July 19, 2023. Found on the internet at https://www.ninds.nih.gov/health-information/public-education/brain-basics/brain-basics-understanding-sleep
6. Osilla, E., et al. Physiology, Temperature Regulation. StatPearls [Internet]. July 30, 2023. Found on the internet at https://www.ncbi.nlm.nih.gov/books/NBK507838/
7. Okamoto-Mizuno, K., et al. Effects of Thermal Environment on Sleep and Circadian Rhythm. Journal of Physiological Anthropology. May 2012. Found on the internet at https://jphysiolanthropol.biomedcentral.com/articles/10.1186/1880-6805-31-14

8. Baniassadi, A., et al. Nighttime Ambient Temperature and Sleep in Community-Dwelling Older Adults. Science of the Total Environment. Nov. 15, 2023. Found on the internet at https://www.sciencedirect.com/science/article/abs/pii/S0048969723042468?via%3Dihub
9. Fujii, H., et al. Fatigue and Sleep Under Large Summer Temperature Differences. Environmental Research. April 2015. Found on the internet at https://www.sciencedirect.com/science/article/abs/pii/S001393511500033X?via%3Dihub
10. Khan, M., et al. The Consequences of Sleep Deprivation and Cognitive Performance. Neurosciences. April 2023. Found on the internet at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10155483/
11. Raj, A., et al. 1214 Higher Bedroom Temperature Associated With Poorer Sleep: Data From Over 3.75 Million Nights. Sleep. May 27, 2020. Found on the internet at https://academic.oup.com/sleep/article/43/Supplement_1/A464/5847198
12. Haghayegh, S., et al. Before-Bedtime Passive Body Heating by Warm Shower or Bath to Improve Sleep: A Systematic Review and Meta-Analysis. Sleep Medicine Reviews. August 2019. Found on the internet at https://www.sciencedirect.com/science/article/abs/pii/S1087079218301552?via%3Dihub

Steven Marshall Author

Steve Marshall has more than 35 years of clinical and leadership experience in health care. He has worked in various settings, including emergency departments, intensive care units, air and ground transport, oncology, infectious disease, and infusion services.  He founded See Doc Nurse Write LLC in 2023 to expand the reach of his clinical knowledge and expertise.

Suzanne Gorovoy Medical Reviewer

Suzanne Gorovoy is a clinical psychologist, behavioral sleep medicine specialist, and member of the Sleep and Health Research Program at the University of Arizona College of Medicine. She received her graduate degree in School Psychology from Teachers College at Columbia University, her PhD in Clinical Psychology from Case Western Reserve University, and completed a postdoctoral fellowship in Behavioral Sleep Medicine at the University of Arizona College of Medicine.

Susan Stiles Reviewer

Susan Stiles, PhD, provides leadership in the design and development of consumer products that inspire, educate, and activate older adults. She’s been instrumental in bringing the Aging Mastery Program® to market and scaling it nationwide via strategic alliances and business partnerships. Stiles has 20+ years of experience in design thinking, multimedia, strategic communications, and management consulting.