Settling the Debate: What Temperature is Optimal for Sleep?
The temperature of your bedroom could be the secret weapon for deeper, more restorative sleep—and most people are getting it wrong.
REST + RECOVERY
Hank Cramblin
8/12/20252 min read
Settling the Debate: What Temperature is Optimal for Sleep?
The Sleep-Temperature Connection
You can have the best mattress money can buy, blackout curtains that would make a Vegas hotel jealous, and a pillow so plush it feels like a cloud—but if your room is too warm or too cold, your sleep quality will take a hit.
Temperature plays a central role in regulating your body’s circadian rhythm—the internal clock that tells you when it’s time to be alert and when it’s time to rest. About an hour before you naturally fall asleep, your core body temperature starts to drop. This cooling is a biological signal that it’s time to power down. If your environment doesn’t support that temperature drop, you’ll have a harder time falling—and staying—asleep.
What’s the Optimal Sleep Temperature?
Most sleep scientists agree that 60–67°F (15.5–19.5°C) is the sweet spot for adults. Within this range, your body can efficiently cool itself and stay in that deeper, more restorative slow-wave and REM sleep.
Go much warmer than 70°F (21°C), and your body struggles to shed heat, leading to more tossing, turning, and micro-awakenings you might not even remember. Drop much below 58°F (14°C), and you risk discomfort that can disrupt deep sleep cycles.
Why Cool Beats Warm for Sleep
Faster Sleep Onset – Cooler temperatures help trigger melatonin release, the hormone that makes you feel drowsy.
Deeper Sleep Stages – Core body cooling is linked to increased time spent in restorative slow-wave sleep.
Reduced Night Sweats – Overheating is one of the most common reasons people wake up in the middle of the night.
Better Heart Health – Studies suggest sleeping cool supports lower nighttime heart rate and blood pressure.
How to Master Your Sleep Climate
Set Your Thermostat – Aim for 65°F as a baseline and adjust within the optimal range to find your personal sweet spot.
Use Breathable Bedding – Natural fibers like cotton, linen, and bamboo wick away moisture and prevent heat buildup.
Cool the Bed, Not Just the Room – Consider cooling mattress pads or gel-infused toppers.
Warm Feet, Cool Core – Wearing light socks can help improve circulation while still allowing core body cooling.
Nighttime Ventilation – A ceiling or floor fan can create airflow without overcooling.
What the Research Says
A 2012 study in Journal of Physiological Anthropology found that cooler bedroom temperatures improved sleep quality and reduced nighttime awakenings. Another study from the Sleep Medicine Reviews journal reinforced that thermal environment strongly impacts sleep onset latency and depth of sleep.
You’re not just getting “more comfortable” by cooling down—you’re optimizing a fundamental biological process.
Bottom Line
Sleep is the ultimate recovery tool, and temperature is one of the most overlooked levers for improving it. Treat your bedroom like a recovery chamber, keep it cool, and let your body handle the rest.