Temperature plays a more significant role in sleep quality than most people realize. If you've ever spent a night tossing and turning because you felt too hot or too cold, you've experienced firsthand how thermal comfort affects rest. But what does the research say about the ideal bedroom temperature?
Research-backed optimal temperature range for sleep
Why Temperature Matters for Sleep
Your body's core temperature follows a circadian rhythm, naturally dropping by 1-2 degrees Fahrenheit as you prepare for sleep and reaching its lowest point in the early morning hours. This temperature decline is a key signal that triggers the release of melatonin and initiates sleep onset.
When your environment is too warm, your body struggles to cool down, making it harder to fall asleep and maintain deep sleep stages. Conversely, if the room is too cold, you may wake up shivering or spend energy trying to stay warm rather than entering restorative sleep phases.
The Thermoregulation Process
During the night, your body dissipates heat through your extremities—particularly your hands and feet. This is why sticking a foot out from under the covers often feels so natural. A slightly cool room supports this heat dissipation process, while a room that's too warm traps that heat and disrupts the natural cooling cycle.
Individual Variation
While 60-67°F works for most people, optimal temperature can vary based on factors like age, metabolism, bedding weight, and personal preference. Women often prefer slightly warmer temperatures than men due to differences in body composition and metabolic rate.
Effects on Different Sleep Stages
Deep Sleep (Slow-Wave Sleep)
Deep sleep is particularly sensitive to temperature. Research shows that a cooler environment helps you spend more time in slow-wave sleep—the stage crucial for physical restoration, immune function, and growth hormone release. When room temperature rises above the optimal range, deep sleep decreases significantly.
REM Sleep
During REM sleep (when most dreaming occurs), your body temporarily loses the ability to regulate temperature effectively—a phenomenon called REM atonia. This makes you more vulnerable to environmental temperature changes during this stage. A room that's too hot or too cold can pull you out of REM sleep entirely.
Practical Tips for Temperature Optimization
Set Your Thermostat Strategically
If you have a programmable thermostat, set it to begin cooling your bedroom about 30 minutes before your typical bedtime. This gives the room time to reach the optimal temperature as you're winding down.
Choose Breathable Bedding
Your bedding matters just as much as room temperature. Consider:
- Natural fibers like cotton, linen, or bamboo that wick moisture and allow airflow
- Temperature-regulating mattress toppers that prevent heat buildup
- Layered blankets so you can easily adjust coverage during the night
- Breathable pillows made from latex, buckwheat, or shredded memory foam
Consider Air Circulation
A ceiling fan or standing fan provides gentle air movement that supports heat dissipation and creates subtle white noise. Even in winter, low fan settings can help prevent stagnant, stuffy air from accumulating.
Take a Warm Shower Before Bed
This might seem counterintuitive, but a warm shower 1-2 hours before bed actually helps you cool down faster. The warm water brings blood to the surface of your skin, and when you step out into cooler air, your body rapidly releases that heat, accelerating the natural temperature drop that signals sleep.
Adjust for Seasons
Your optimal temperature may shift slightly between summer and winter as your body acclimates to seasonal changes. Pay attention to how you sleep and be willing to adjust your thermostat by a degree or two.
Hot Sleeper Tips
If you consistently run warm at night, consider a cooling mattress pad, moisture-wicking sleepwear, and keeping a glass of cold water on your nightstand. Some people benefit from cooling pillows with gel inserts or phase-change materials.
When Partners Have Different Preferences
It's common for sleep partners to have conflicting temperature preferences. Some solutions include:
- Using separate blankets with different weights or materials
- Investing in a dual-zone mattress pad that allows different temperature settings on each side
- Aiming for the cooler partner's preference and providing the warmer partner with additional blankets
- Adjusting clothing—one partner might wear light pajamas while the other wears warmer sleepwear
Signs Your Bedroom Is the Wrong Temperature
Pay attention to these indicators that your sleep environment might be too warm or cold:
- Frequently waking up during the night
- Waking up sweating or with damp sheets
- Feeling uncomfortably cold when you wake up
- Taking a long time to fall asleep
- Restless sleep with lots of position changes
The Bottom Line
Optimizing your bedroom temperature is one of the simplest and most effective changes you can make for better sleep. Start with a setting around 65°F (18°C) and adjust based on your personal comfort. Pay attention to your bedding choices, and don't hesitate to experiment until you find what works best for you.
Small temperature changes can yield significant improvements in sleep quality. Give your thermostat some attention, and you might be surprised at how much better you rest.