How temperature impacts sleep and 5 tips for staying at your “coolest”
For many of us, an ideal sleep environment is something like this: a dark, quiet room with lots of heavy blankets and pillows, our favorite pajamas, and a mattress with our preferred firmness and bounce. While all of this appears to be a detail-oriented dreamworld, there’s one crucial downfall to this “perfect” sleep environment: temperature.
Research has shown that sleeping in a room with a specified temperature range is best to achieve restorative sleep. Our body temperature fluctuates across the night, guiding us through various phases of sleep. This process is driven by our inner biological clock that ticks close to a speed of 24-hours.
Beyond nighttime sleep, studies have shown that your body’s temperature also operates on a similar 24-hour schedule. We are at our “coolest” in the very early morning (around 4 a.m.), and gradually warm up again as we leave sleep and cross over into wakefulness.
Because of our biology, we should sleep in a slightly cool room, at a temperature between 60 and 67 degrees. 65 degrees is the optimal temperature many sleep professionals agree on. This is because our body’s temperature dips slightly during certain phases of sleep—the phase of dreaming—and having an environment that isn’t competing with our internal thermostat can make for a more restful experience.
Interested In Better Sleep?
The ultra-compact SleepTunerTM is like a sleep lab that fits in your pocket. SleepTuner is the smallest wearable that can reveal how your breathing and position impact your sleep quality.Learn More
Trying to sleep in an environment that is too warm can be tricky. It takes longer to fall and stay sleep when it’s hot, and the phase of sleep where dreams occur can be fragmented or completely absent. How can you ensure a cooler, more comfortable sleep experience for yourself and your loved ones?
Here are some ideas:
- Drink water. Hydrating your body before sleep can help keep it cool. On especially hot days, when you’re extra sweaty, replenishing water and electrolytes lost through perspiration is very important.
- Keep cool. Some people feel more comfortable under a pile of blankets, perhaps as a holdout from when they were young. But often, it’s just the feeling of being covered that makes us comfortable, rather than actually being beneath layers of heavy blankets. Try sleeping with just a top sheet, which gives the sensation of being covered but is far less hot. If you must sleep with blankets, sleep naked. You won’t have to worry about the non-cooling, insulating components of pajamas. Another approach is to wear a pair of socks, which provide insulation to our extremities that don’t receive much blood flow while lying down, but minimally impacts our core temperature.
- Heat rises. Do you live or sleep above the ground floor of your building? Heat travels upward, and all the energy from appliances, other humans, and the natural movement of warmer air can make your living space warmer. Counteract this effect by allowing air to blow through your windows, and closing your blinds to keep the sun out during the hottest parts of the day.
- Allow your bed to breathe. Special sheets, mattresses, pillows and pajamas that claim to cool down your sleep environment are widely available in today’s market. If your budget allows, give them a try and see if they work for you. If you’d rather not spend the money, sleep in breathable clothing (or naked!), use bed linens only, and ensure that your head remains uncovered as a natural way to stay cool at night.
- Make cool part of your routine. A slight dip in temperature before you actually retire to bed can send physiological signals to your body that hibernation is imminent, enabling you to fall asleep faster. Taking a cool shower or sipping chilled water (not alcohol) can help. Experiment with this as part of your nightly wind-down routine and see if it improves your sleep quality.
Temperature regulation during sleep can be tricky at first. Everyone’s preferences are a little different, and when you add in a bed partner and their own body heat affecting temperature, it can complicate things further. So take some time to experiment with different techniques until you find a combination that leaves you cool, calm, and well-rested.
CPT Allison Brager, PhD is a neurobiologist serving as an active duty Army officer with expertise in sleep and chronobiology. She currently serves as a sleep scientist in the Center for Military Psychiatry and Neuroscience at the Walter Reed Army Institute of Research, the largest and most diverse biomedical sleep research laboratory in the Department of Defense. She sits on the Federal Fatigue Management Working Group and has contributed to Army Doctrine on Holistic Health and Fitness through the Office of the Surgeon General. She consults with US Olympic, big-time collegiate, and professional sporting teams. CPT Brager recently received eight golds at the Gay Olympics in Paris, France, is an active competitor in Crossfit® and former Reebok Crossfit® Games team athlete, has coached NCAA decathletes and pole-vaulters, and a four-year varsity letterman in Division 1 Track and Field at Brown University.