Recommending a specific range is difficult, Downey and Heller say, because what is comfortable for one person isn’t for another (explaining how Roy’s wife slept blissfully in the chilly 60-degree room). While a typical recommendation is to keep the room between 65 and 72 degrees Fahrenheit, Heller advises setting the temperature at a comfortable level, whatever that means to the sleeper.
Doheny, K. (2010). Can’t Sleep? Adjust the Temperature. WebMD. Retrieved August 31, 2014, from http://www.webmd.com/sleep-disorders/features/cant-sleep-adjust-the-temperature
Looking at the available research, most studies agree that a temperature between 60 and 67 degrees Fahrenheit is optimal for sleeping, with temperatures above 75 degrees and below 54 degrees disruptive to sleep. Body temperature has also been linked to the amount of deep sleep an individual gets during the night, with cooler body temperatures leading to more deep sleep. Sleeping in a hot environment has also been shown to increases wakefulness and decreases slow wave sleep. The addition of high humidity can intensify the effect of heat.
Winter, C. (2013, October 10). Choosing the Best Temperature for Sleep. Huffington Post. Retrieved August 31, 2014 from, http://www.huffingtonpost.com/dr-christopher-winter/best-temperature-for-sleep_b_3705049.html
“Temperature regulation is a significant factor in each of the two types of insomnia. The difference is when the insomnia occurs. People with sleep onset insomnia have difficulty initiating sleep at the beginning of the night, taking two to four hours each night in the worst cases….”
“Studies of sleep onset insomniacs show that they consistently have a warmer core body temperature immediately before initiating sleep, when compared with normal healthy adults. This results in a state of heightened arousal that prevents them from falling asleep when they go to bed, probably because they have to wait for their bodies to lose the heat that’s keeping them awake. We’re only talking about a half to one degree but that small temperature change can result in significant differences in arousal between insomniacs and people without sleeping problems,” Dr Van den Heuvel says.
Hinter, G. (2004). Getting to the core of insomnia. UniSANews. Retrieved August 31, 2014 from http://w3.unisa.edu.au/unisanews/2004/June/insomnia.asp
Studies have found that in general, the optimal temperature for sleep is quite cool, around 60 to 68 degrees Fahrenheit. For some, temperatures that fall too far below or above this range can lead to restlessness.
O’Connor, A. (2009, August 3). The Claim: Cold Temperatures Improve Sleep. Retrieved August 31, 2014 from http://www.nytimes.com/2009/08/04/health/04real.html?_r=0
Extreme temperatures at either end of the range can affect sleep. A hot room (more than 24° C [75.2° F]) can cause restless body movements during sleep, more nighttime awakenings, and less dream type sleep. A cold room (less than 12° C [53.6° F]) can make it difficult to get to sleep and can cause more unpleasant and emotional dreams. We recommend room temperature to help promote sleep for most people is, therefore, around 18° C [64° F].
Morin, C.M. (2003, June 30). Insomnia: A Clinician’s Guide to Assessment and Treatment. Springer Science & Business Media. p. 51.
Research shows that the ideal temperature range for sleeping varies widely among individuals, so much so that there is no prescribed best room temperature to produce optimal sleep patterns. People simply sleep best at the temperature that feels most comfortable. That said, extreme temperatures in sleeping environments tend to disrupt sleep. REM sleep is commonly more sensitive to temperature-related disruption. For example, in very cold temperatures, we may be deprived entirely of REM sleep.
Division of Sleep Medicine at Harvard Medical School. (2007). External Factors that Influence Sleep. Retrieved August 31, 2014 from http://healthysleep.med.harvard.edu/healthy/science/how/external-factors