In the winter months, we look forward to going to bed, slipping under the warm covers, and falling into a deep slumber. While a warm and cozy room is inviting, some science suggests that keeping bedrooms on the cooler side could help improve health, from burning more calories to getting a better night’s sleep. (Try these yoga poses for better sleep.)
So, how cold should you go? Around 19 degrees Celsius may be the ideal temperature. A 2014 study published in the journal Diabetes found men who slept in rooms cooled to 66 degrees Fahrenheit (19 degrees Celsius) for a month increased their levels of calorie-burning brown fat by 42 percent and their ability to metabolize fat by 10 percent. (The men slept with just bedsheets.) These men also showed improvement in their insulin sensitivity, potentially lessening their risks of developing type 2 diabetes. While the study’s sample size was small—five healthy men with an average age of 21—it suggests some potential in terms of type 2 diabetes prevention. (Psst: Learn all the benefits of sleeping naked.)
Researchers believe that in a cool space, our bodies have to work harder to raise our core temperature to 98.6 degrees Fahrenheit—the “normal” body temperature, although this varies from person to person. More work means more calories torched. “Lowering the room temperature before sleep turns on your body’s thermoregulatory functions to keep you warm,” explains Bridgette Agee, RN, a registered nurse and the Bariatric Program manager at the Marina Weight Loss Center at Cedars-Sinai Marina Del Rey Hospital in Marina Del Rey, California. “The action also activates brown fat cells that require energy from the white fat stores, and this borrowing of sorts helps to decrease the amount of white fat or ‘body fat’ in the body.” She adds that rest is essential during this process to rejuvenate or reset your metabolism. (Check out how many calories you burn when sleeping.)
You may also be able to fall asleep easier in a cooler room, according to the National Sleep Foundation. A study published in the Journal of Physiological Anthropology found snoozing in warmer temperatures can increase wakefulness and decrease both slow-wave and REM sleep. In addition, humid heat increases the thermal load during sleep, impacting sleep stages and thermoregulation. (Psst: Check out the things your sleep habits are trying to tell you.)
A good night of sleep can also lead to a host of other health benefits, such as protecting your brain from Alzheimer’s disease, improving immune-system function, boosting your productivity, and fighting aging. The Centers for Disease Control and Prevention notes that sleep can also help to prevent or control a number of chronic illnesses, including type 2 diabetes, cardiovascular disease, obesity, and depression. And, of course, it can also improve your mood and make you feel better.
The bottom line: A cool(er) room may be optimal not just for a good night’s sleep, but your overall health.
Next, learn other ways you can boost your metabolism.