Our hunter-gatherer ancestors slept mostly in caves that were cool, chilly, and cold as the seasons changed. Caves, which were common sleeping quarters, rarely, if ever, get hot.
Is it possible that we have genetically evolved to thrive when we sleep in a cold room versus a warm or hot room?
This bit of ancient wisdom is backed by a surprising amount of science.
Studies show that sleeping in a cold room—between 60 and 67 degrees Fahrenheit—can help us lose weight, stabilize healthy blood sugar levels, boost immunity, and trigger healthy production of melatonin (one of our primary longevity hormones).
In one study, a group of healthy young men were acclimatized to sleeping in a colder bedroom.
After just 8 weeks of sleeping in a 66 degree room, the amount of brown fat or good fat they had doubled. Brown fat has been linked to better metabolic health, stable weight, and overall greater health.
The next month, when they slept in an 81 degree room, they lost the brown fat.
In fact, they had less brown fat after the month sleeping in an 81 degree room for a month than when they started the study—and remember, they were healthy to begin with. (1)
After one month of sleeping in a 66 degree room, the men also burned more calories and had greater insulin sensitivity, which is essential for healthy blood sugar levels. (1)
Ayurvedically, the sleeping hours between 10 pm and 2 am are the pitta hours of the night, where the body moves into detox mode driven by the hormone, melatonin.
Sleeping in a hot room at the time of night where the body is naturally heating up makes for a perfect storm of sleeplessness. If your body type is also pitta, you are in the summer months and, God forbid, in the tropics, keeping your core temperature down to support deep sleep will be a true challenge.
In the early evening, the body’s core temperature becomes lower. This is one of the mechanisms that help us get sleepy. This is accompanied by a reduction in the daytime stress hormone, cortisol, and a surge of the sleep and longevity hormone, melatonin.
Sleeping in a cool room can boost melatonin levels, while sleeping in a warm or hot room can suppress melatonin and disturb your sleep quality. (2,3)
In fact, in one study, the hypothermic (cold-loving) properties of melatonin may be responsible for at least 40 percent of the regulation of the body’s circadian rhythm. (2)
This may be the most important reason of all to sleep in a colder room. Melatonin is not just a hormone that puts you to sleep, but a hormone that regulates all of the hormones of the body and governs many of the body’s immune, microbiome, cardiovascular, metabolic, psychological, and detox functions.
According to the study mentioned above, supplemental melatonin and sleeping in a colder room may be an effective strategy to reset the circadian clock for better sleep and detox at night, but also to have more energy, better digestion, mood and metabolic function during the day. (2,3)
Insomnia and Body Temperature
Studies show that when the body’s core temperature rises during the night, there is a greater tendency to wake up and for sleep to be disturbed. (4)
Keeping the body’s core temperature lower while sleeping has shown to support deeper, longer and better quality of sleep. In fact, a cooler environment before sleep may help induce sleepiness and make it easier to fall asleep. Keeping the room cool throughout the night may be just what you need to stay asleep! (4,5,6)
The cumulative benefits of sleeping in a cool room, preferably in the mid to low 60’s, may not only offer long-term benefits for better sleep, greater health and longevity, but also the accumulation of more brown fat, better blood sugar, better calorie-burning efficiency during the day and healthier melatonin production during the night.
Low-Dose Melatonin Supplementation for a Sleep Circadian Reset
I suggest using a very low dose of melatonin about 45 minutes before going to sleep in a cool, 66 degree or less bedroom for 3 months as a quick reset.
I formulated our Liquid Melatonin to make it very easy to get a low dose. One drop of the Liquid Melatonin is .1 mg of melatonin. I suggest taking between 1-10 drops before bed.
Build up slowly until you find a dose that offers both deeper sleep and a refreshed feeling upon waking. More is not better here! While any dose of melatonin is proven safe, less is always more when it comes to melatonin.