Why a Cooler Bedroom Temperature Helps You Sleep Better

From healthcare.utah.edu

Hot summer nights can make it harder to fall asleep—and stay asleep. If you’ve been waking up sweaty or lying awake long after bedtime, your bedroom temperature could be part of the problem.

Chitra Lal, MD,  clinical professor of pulmonary, critical care, and sleep medicine and director of University of Utah Health’s Sleep Wake Center, has helped many patients overcome persistent sleeplessness by troubleshooting a common culprit: body temperature.

Small changes to your sleep environment, paired with simple lifestyle habits, can help you wind down and improve the quality of your rest.

Simple Habits to Help You Sleep Better

As bedtime approaches, your core body temperature naturally drops by 1–2°F. Setting your thermostat at 65–67°F can help support that process, although older adults may feel more comfortable slightly warmer—around 67–74°F.

A bedroom that is too warm can make it harder to get quality sleep by causing you to:

• Take longer to fall asleep
• Wake up more often during the night
• Get less REM and slow‑wave (deep) sleep
• Feel less rested in the morning

Your bedding matters, too. During the summer, choose breathable fabrics like cotton or linen fabrics. In colder months, switch to insulating fabrics like microfleece, but avoid using anything too warm that disrupts your body’s natural cooling process.

A cooler room works best when paired with healthy sleep habits. Lal also recommends these simple steps to help your body wind down each night:

• Keep the room dark.
• Skip caffeine within three to four hours of bedtime.
• Avoid alcohol within four to six hours of bedtime.
• Don’t watch TV or scroll on your phone in bed.
• Go to bed only when you’re ready to sleep.
• Clean your humidifier regularly if you use one.
• 
  

Time Your Light Exposure

Temperature isn’t the only thing that affects your body’s internal clock. Light exposure also plays an important role in helping your body know when it’s time to sleep—and when it’s time to wake up.

It’s true that blue light disrupts sleep, but when timed correctly, it can actually help regulate your circadian rhythm. Here’s how to use it to your benefit:

Avoid blue light before bed

Put devices away at least a couple of hours before bed or switch them to ambient/night mode. Research has shown that evening blue light:

• Delays sleep
• Pushes your internal clock later
• Makes it harder for your core temperature to drop

Use blue light in the morning

Early morning blue light can shift your circadian rhythm earlier and strengthen your natural wake‑up signal. You can find blue‑light therapy lamps at most major retail stores including pharmacies, department stores, and online shops.

https://healthcare.utah.edu/healthfeed/2026/08/why-cooler-bedroom-temperature-helps-you-sleep-better