What is the Best Temperature for Sleep?


Many people have experienced the struggle of falling asleep during a particularly cold winter or hot summer. However, even small changes in ambient temperature (1) can greatly impact sleep quality.

Our bodies rely on circadian rhythms (2), which are internal biological processes that regulate our bodies over a 24-hour period, to know when to wake or to sleep. Because our circadian rhythms typically align with the rise and fall of the sun, light and temperature play large roles in preparing our bodies for sleep.

Determining what temperature to keep your bedroom can help promote quality rest by signaling to your body that it is time to sleep.

What Is the Best Temperature for Sleeping?

Although some sleep researchers identify an optimal room temperature (3) as falling between roughly 66 degrees Fahrenheit (19 degrees Celsius) and 70 degrees Fahrenheit (21 degrees Celsius), everyone’s body and needs are different. Each person’s optimal sleeping temperature may vary by a few degrees, with many experts recommending sleepers keep their bedrooms on the cool side at night.

What Is the Best Temperature for Infants?

Parents should be aware that an overly hot room can increase the risk of sudden infant death syndrome (4). Experts recommend parents monitor their baby’s temperature (5) throughout the night by touching the stomach or back of the neck. Parents can also set up a thermostat to more closely control room temperature. Avoiding improper bedding and clothing (6) can also help keep your baby safe throughout the night.

How Does Temperature Affect Sleep?

Our circadian rhythm largely determines when our bodies are alert and awake versus ready to sleep. This cycle is informed by exposure to sunlight and controlled by a part of the brain called the suprachiasmatic nucleus (7). This part of the brain uses numerous environmental clues, including light and temperature, to know when to initiate sleep.

Our internal body temperature typically falls around 98.6 degrees Fahrenheit (37 degrees Celsius) (8). However, throughout the night, the body uses a process called vasodilation (9) to send blood flow to the extremities and lower the core temperature by a couple degrees. Vasodilation is why some individuals experience warm hands or feet as they fall asleep, and why those with cold feet may struggle with insomnia.

This drop in internal temperature also coincides with the release of sleep hormones (10), which helps initiate sleep and promote quality rest.

What Happens to the Sleeping Body in Warm Temperatures?

Because our bodies rely on a drop in temperature to fall asleep, a warmer bedroom can lead to tossing and turning instead of quality sleep. Research also suggests that sleeping too hot (11) can reduce sleep efficiency, which can lead to fatigue (12) over time.

Some studies have shown a correlation between higher core temperatures and a decrease in time spent in important sleep stages, such as slow-wave sleep (13) and REM sleep (14). These sleep stages are crucial for the body to adequately recover throughout the night.

Ways to Create a Comfortable Sleep Environment

It can be difficult to turn a hot and stuffy room into a cool and comfortable place to sleep, but there are ways to bring down the temperature and promote better rest.

  • Turn on the AC: In stuffy rooms that tend to stay warm, turning on the air conditioning or lowering the thermostat can help encourage the body to rest.
  • Invest in Breathable Bedding: There are many mattresses, pillows, and other types of bedding that are specifically designed to stay cool throughout the night. Investing in temperature-neutral bedding can help sleepers avoid overheating.
  • Change Bedding with the Seasons: Switching to lightweight bedding in the summer and heavier, more insulating bedding in the winter is another way that sleepers can control their temperature throughout the year.
  • Keep It Dark: Like temperature, light plays a large role in preparing our bodies for sleep. Keeping your room dark can help signal to your body that it is time to sleep.
  • Remove Distractions: Avoiding loud noises such as television or music can help prevent disruptions that could interrupt quality rest. For those who prefer some gentle noise, a white noise machine or app can replace louder sounds.
  • Avoid Screens and Caffeine Close to Bedtime: Your bedtime behaviors can also impact your ability to get quality rest. The blue light from screens can interfere with your natural circadian rhythm and make it difficult to sleep, and caffeine can lead to insomnia or restlessness. Avoiding screens and caffeine before bed can help you fall asleep faster.

Finding the ideal room temperature may make it easier to fall asleep at night and improve your overall sleep quality.



+ 14 Sources
  1. 1. Accessed on March 8, 2021.https://pubmed.ncbi.nlm.nih.gov/22738673/
  2. 2. Accessed on March 8, 2021.https://pubmed.ncbi.nlm.nih.gov/30137792/
  3. 3. Accessed on March 11, 2021.https://pubmed.ncbi.nlm.nih.gov/31105512/
  4. 4. Accessed on March 8, 2021.https://www.ncbi.nlm.nih.gov/books/NBK513376/
  5. 5. Accessed on March 8, 2021.https://pubmed.ncbi.nlm.nih.gov/33061911/
  6. 6. Accessed on March 8, 2021.https://safetosleep.nichd.nih.gov/resources/caregivers/environment/look
  7. 7. Accessed on March 8, 2021.https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/understanding-Sleep
  8. 8. Accessed on March 8, 2021.https://www.ncbi.nlm.nih.gov/books/NBK331/
  9. 9. Accessed on March 8, 2021.https://www.ncbi.nlm.nih.gov/books/NBK557562/
  10. 10. Accessed on March 8, 2021.https://pubmed.ncbi.nlm.nih.gov/29318587/
  11. 11. Accessed on March 8, 2021.https://pubmed.ncbi.nlm.nih.gov/30669302/
  12. 12. Accessed on March 8, 2021.https://pubmed.ncbi.nlm.nih.gov/19956456/
  13. 13. Accessed on March 8, 2021.https://pubmed.ncbi.nlm.nih.gov/29247670/
  14. 14. Accessed on March 8, 2021.https://pubmed.ncbi.nlm.nih.gov/22738673/

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