Temperature plays a crucial role in the body’s ability to achieve restorative sleep, and research shows that sleeping in a warm room can interfere with both the quality and duration of rest. While a cozy, heated bedroom may feel comfortable at first, it disrupts the natural processes the body relies on to fall asleep and stay asleep throughout the night.
The body’s core temperature naturally drops by about one to two degrees Fahrenheit as part of the circadian rhythm, signaling that it is time to rest. According to the National Institute of Neurological Disorders and Stroke, this cooling is essential for the initiation of sleep. When the room is too warm, the body struggles to achieve this natural temperature drop, delaying the onset of sleep and leading to more nighttime awakenings.
Research published in the journal Sleep Medicine Reviews highlights that thermal environments strongly influence sleep cycles, particularly slow-wave sleep and REM sleep, which are critical for physical restoration and memory consolidation. Warm sleeping conditions reduce the amount of time spent in these deeper sleep stages, leaving individuals feeling less refreshed in the morning.
A study from the Journal of Physiological Anthropology found that higher bedroom temperatures increase restlessness, causing people to toss and turn more often. This fragmented sleep not only reduces quality but also impacts overall health by increasing stress hormone levels. Elevated nighttime body temperatures have been associated with higher levels of cortisol, which can interfere with relaxation and prolong feelings of fatigue the next day.
The negative impact of sleeping in a warm room extends to long-term health as well. Research in Environmental Health Perspectives shows that poor sleep due to heat exposure is linked to an increased risk of cardiovascular disease, obesity, and metabolic disorders. Chronic disruption of sleep cycles caused by a warm environment can also impair cognitive performance, mood regulation, and immune system function.
Experts generally recommend keeping the bedroom temperature between 60 and 67 degrees Fahrenheit for optimal sleep. Cooling strategies such as using breathable bedding, keeping windows slightly open for airflow, or running a fan or air conditioner can help create a sleep-friendly environment. These adjustments support the body’s natural cooling process and allow for deeper, more restorative rest.
Disclaimer: This article is for informational purposes only and is not intended as medical advice. If you experience persistent sleep disturbances or difficulty regulating your sleep environment, consult with a healthcare provider for personalized guidance.
References:
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National Institute of Neurological Disorders and Stroke. (2020). Brain basics: Understanding sleep. Retrieved from https://www.ninds.nih.gov
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Okamoto-Mizuno, K., & Mizuno, K. (2012). Effects of thermal environment on sleep and circadian rhythm. Journal of Physiological Anthropology, 31(1), 14.
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Caddick, Z. A., Gregory, K., Arsintescu, L., & Flynn-Evans, E. E. (2018). A review of the environmental parameters necessary for sleep. Sleep Medicine Reviews, 42, 56–67.
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Obradovich, N., Migliorini, R., Mednick, S. C., & Fowler, J. H. (2017). Nighttime temperature and human sleep loss in a changing climate. Science Advances, 3(5), e1601555.
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Environmental Health Perspectives. (2017). Climate change and sleep disturbance: Heat exposure’s impact on health.