If you usually keep your bedroom temperature around 78 degrees Fahrenheit, you may be all too familiar with the discomfort of waking up drenched in sweat.
To feel refreshed and recharged in the morning, sleep experts recommend setting your air conditioner to 70 degrees or lower. This strikes a balance between a comfortable sleeping environment and efficient energy use.
While programs like Energy Star, run by the U.S. Environmental Protection Agency and the Department of Energy, suggest setting thermostats between 78 and 82 degrees for sleeping, sleep specialists strongly disagree. They argue that such warmth could make the bedroom environment feel uncomfortably chilly due to disrupted sleep patterns.
Sleep psychologist Dr. Michelle Drerup advises treating your bedroom like a “cave,” maintaining a temperature of 60 to 67 degrees for optimal rest. “It should be cool, dark, and quiet to promote better sleep,” Dr. Drerup tells the Cleveland Clinic. “If your bedroom becomes too warm or cold, you’re more likely to wake up. Our bodies naturally cool during sleep to achieve deeper restorative stages, which are vital for a good night’s rest.”
Indeed, studies confirm that extreme heat or cold can lead to more awakenings and reduced rapid eye movement (REM) sleep—the phase when dreaming occurs. “Maintaining proper thermoregulation is essential for restorative, slow-wave sleep,” Dr. Drerup adds, noting that these are the most rejuvenating stages of rest.
Striking the Perfect Temperature Balance
The Sweat Factor
During sleep, the body releases heat to lower its core temperature. To support this natural process, experts suggest keeping the bedroom cool, as temperatures above 70 degrees can lead to discomfort. This warmth, especially under blankets, often results in sweating, restlessness, and disrupted sleep. “Heat is a major disruptor of REM sleep,” Dr. Drerup emphasizes.
Humidity and Stickiness
While warm temperatures may be tolerable during the day, they can create a sticky and unpleasant atmosphere at night. In humid climates, higher AC settings can fail to effectively dehumidify the air, leaving rooms damp and uncomfortable. This can aggravate respiratory issues and add to the discomfort.
Energy Inefficiency
Setting the air conditioner to 78 degrees might seem energy-efficient, but it often takes longer to cool the room, especially on hot nights. This extended cooling time can increase energy use rather than reduce it.
Health Risks
Overheating at night can cause headaches, dehydration, and restlessness. People with asthma or other conditions may find their symptoms worsening due to the heat.
Poor Sleep Quality
Warmer environments can lead to frequent awakenings and difficulty falling asleep, leaving you groggy and irritable in the morning. Uneven air circulation at 78 degrees can also create hot spots in the room, reducing overall comfort.
Compromised Air Quality
Higher temperatures can reduce air conditioner efficiency in removing allergens and pollutants, leading to poorer air quality. This is particularly troublesome for those with respiratory conditions.
Disrupted REM Sleep
Warmer temperatures can prevent your body from reaching the cooler conditions necessary for REM sleep, leading to reduced cognitive function, mood swings, and a sense of fatigue upon waking.
Rethinking Energy Savings
Although keeping the AC at 78 degrees may appear cost-effective, the savings are often minimal. Lowering the temperature slightly can cool the room more quickly, allowing the air conditioner to shut off sooner and consume less energy overall. Repeated thermostat adjustments to find a comfortable setting can also drive up energy usage.
The Ideal Range for Restful Sleep
To promote restorative sleep, improve air quality, and maintain energy efficiency, experts recommend setting your air conditioner between 60 and 67 degrees Fahrenheit. This range fosters a cool, comfortable environment that supports better health and overall sleep quality.