Temperature: The Key to Quality Sleep

Temperature and Its Role in Sleep and Productivity

Your body needs to drop 2 degrees to fall asleep, emphasizing the important role temperature plays in achieving restful sleep. Additionally, every circadian cycle, approximately 24 hours, you undergo a temperature peak and a temperature minimum. During your temperature peak, which is around early afternoon, you experience enhanced mental clarity and physical performance. After the peak, your body starts to cool down and prepare for sleep. Learning how to control your environment's temperature during the day is a strong tool for better sleep and thus better performance during the day.

Understanding Your Circadian Rhythm and Its Impact on Your Body

Your circadian rhythm is the biological clock that tells all your cells when to perform their functions. The thing is, each individual cell has its own clock so sometimes the clocks are not in sync. For example, when dealing with jet lag, you may experience high levels of energy when you want to sleep and exhaustion when you want to work. This inconvenient use of energy occurs because your biological clock is still aligned with your previous time zone, providing energy when it was typically needed there. Keeping all your cells' clocks in sync is crucial for high-quality sleep, strong immune function, and improved focus.

The Role of Temperature in Enhancing Sleep Quality

As noted above, temperature is a keystone factor regarding sleep. Maintaining a cool sleep environment is vital to achieving better and deeper sleep. A 2012 study by Mizuno and Mizuno found that people sleeping in uncomfortably warm environments experienced less deep sleep and more frequent wake ups. Addionally, a 2023 systematic review by Chevance et al. indicated that in regions where air conditioning is not available, lower sleep quality is experienced by the general population during the warmer months. A medically reviewed WebMD article found that setting the thermostat between 60 and 65 degrees Fahrenheit yielded the best results. However, setting your room’s temperature to whatever feels comfortable is the most important factor. Remember, people always vary in preferences and only you know what is best for you. Keeping with that theme, I recommend safely experimenting with different temperatures and seeing which works best for you.

Using Temperature to Fight Jet Lag

Temperature can have a strong influence on your circadian rhythm. When dealing with jet lag giving your temperature maximum and minimum a little push can go a long way. When recovering from jet lag, every indicator of your new time zone is useful for your body. An easy habit to implement is when traveling to a new time zone, during early evening when you should be experiencing your temperature maximum, put on more clothes and find a way to heat your body. Then, later in the evening, put yourself in a cooler environment, making your core body temperature colder, which is what your body would be doing naturally. This practice will allow you to fall asleep much easier and have more energy. Additionally, you will adjust to a new time zone quicker and smoother.

Citations

Sleep Toolkit: Tools for Optimizing Sleep & Sleep-Wake Timing | Huberman Lab Podcast #84

How to Defeat Jetlag, Shift Work & Sleeplessness

What it means when you're tired during the day but have a sudden burst of energy before bedtime

A systematic review of ambient heat and sleep in a warming climate

What’s the Best Temperature for Sleep?

Van Someren, E. J. W. (2006). Mechanisms and functions of coupling between sleep and temperature rhythms. Progress in Brain Research, 153, 309-324. doi:10.1016/S0079-6123(06)53018-3

Cagnacci, A., Elliott, J. A., & Yen, S. S. C. (1992). Circadian rhythm of core body temperature in elderly men and women. Chronobiology International, 9(4), 403-412. doi:10.3109/07420529209064542

Lack, L., & Wright, H. (2007). Clinical management of delayed sleep phase disorder. Behavioral Sleep Medicine, 5(1), 57-76. doi:10.1080/15402000601182411

Schmidt, C., Collette, F., Cajochen, C., & Peigneux, P. (2007). A time to think: Circadian rhythms in human cognition. Cognitive Neuropsychology, 24(7), 755-789. doi:10.1080/02643290701754158

Edwards, B. J., Waterhouse, J., & Reilly, T. (2002). Circadian rhythms and exercise — Review article. Sports Medicine, 32(11), 685-701. doi:10.2165/00007256-200232110-00001

Okamoto-Mizuno, K., & Mizuno, K. (2012). Effects of thermal environment on sleep and circadian rhythm. Journal of physiological anthropology, 31(1), 14. https://doi.org/10.1186/1880-6805-31-14