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Key Takeaways
- Bedroom temperatures of 75 degrees Fahrenheit or lower may be better for heart health than warmer temperatures.
- Cooler nighttime temperatures can improve sleep quality and help your body rest and repair itself.
Keeping your bedroom at 75 degrees or lower may help you sleep better at night and support a healthier heart.
Aim for 75 Degrees or Less
A 2025 study examined sleep, temperature, and signs of stress among 47 adults aged 65 and older. Participants wore health tracking devices for researchers to monitor their heart rate and heart rate variability (HRV) overnight. They also used in-room sensors to measure the bedroom temperature.
The study found that bedroom temperatures greater than 75 degrees were associated with:
- Increased heart rate
- Shift toward a dominant sympathetic nervous system (fight or flight)
- Greater signs of physiological stress
These signs of bodily stress increased with rising temperature, suggesting that cooler nighttime temperatures may be better for the heart.
How Sleep and Temperature Are Linked
People generally prefer sleeping in cooler temperatures and, in doing so, report sleeping for longer and feeling more rested when they wake up. There's evidence that as temperatures rise, it becomes more challenging to get sufficient, high-quality sleep.
One animal study found that cooler temperatures trigger the body to produce melatonin. Melatonin is a signaling molecule that helps regulate the sleep-wake cycle, and higher levels can make you feel sleepy. It also helps regulate the immune system and increases tolerance to stress. However, this effect has not been studied in humans.
Another connection is simply that when it's too hot, you can feel uncomfortable and sweaty, making it harder to fall asleep.
Why Heart Health May Also Benefit From Cooler Bedroom Temperatures
Heat places extra demands on your body's cardiovascular system. When it's hot, your heart works harder to circulate blood and keep your body cool. For this reason, warmer bedroom temperatures are more stressful for your body, while cooler ones are more soothing.
Sleep temperature may indirectly affect heart health by influencing sleep quality and duration. If you regularly sleep in a room that's too hot, you may sleep poorly, which could affect your heart. Your body rests and repairs itself during sleep, and if you're not getting quality sleep, this could affect your heart.
What's The Best Temperature to Keep Your Bedroom at Night?
The World Health Organization (WHO) recommends keeping indoor daytime temperatures below 79 degrees. However, there are no equivalent nighttime temperature recommendations. The study above indicates that cooler nighttime temperatures of 75 degrees or less may benefit heart health.
Some experts recommend keeping your nighttime bedroom temperature even cooler: between 65 and 69 degrees. The trick is to avoid having your bedroom too hot or too cool, because shivering through the night can make it tough to get good-quality sleep.
Your ideal sleeping temperature may also depend on factors like your muscle composition or body fat, which can help insulate you against cooler temps.
If you have a wearable fitness tracker, it may be worth experimenting with different sleep temperatures and tracking how your sleep responds to them.
How to Keep Your Bedroom Cool
Turning on the air conditioning is the simplest way to cool your bedroom, but it's not always reasonable for everyone. Lots of people around the world don't have air conditioning or are aiming to cut their electricity bills.
If air conditioning isn't an option, consider other ways to lower your bedroom's temperature or, alternatively, your body's temperature. Some strategies include:
- Keep windows open
- Use a fan
- Set ice cubes under a fan to increase coolness
- Use light sheets or a "summer duvet" instead of a heavy duvet
- Wear lightweight pajamas
- Avoid exercise at night
- Skip caffeine, alcohol, and spicy food in the evening
- Take a hot bath before bed (this one might sound counterintuitive, but as your body cools off afterward, your core body temperature drops and makes you feel sleepy)
Read the original article on Verywell Health
