Sleeping in the right environment is more powerful than many realize, and temperature plays a surprisingly vital role in the quality of our sleep. According to Dr. Kelvas and other experts, when your room is too hot or cold, your body struggles to regulate essential hormones like melatonin and cortisol. This imbalance can prevent you from falling asleep or staying asleep through the night. That’s why the Sleep Foundation recommends keeping your bedroom between 60°F (15.5°C) and 68°F (20°C) — a range that supports your body’s natural thermoregulation and helps you transition smoothly into deep, restorative sleep.
Thermoregulation—the body’s internal temperature-balancing system—works through processes like sweating, shivering, and blood vessel dilation or constriction. These systems play a critical role in sleep preparation. As you wind down, your core body temperature naturally drops by about 2°F, a cue for the brain to begin shutting down for rest. A cool room accelerates this process, boosting melatonin production while limiting cortisol levels. Conversely, a hot or humid room can disrupt this delicate system, reducing REM and slow-wave sleep, increasing wakefulness, and even causing night sweats. Research shows that even mild heat exposure in elderly individuals significantly increased wake time and reduced overall sleep quality. Cold rooms, if too cold, may force the body to burn energy to stay warm, preventing it from sinking into deeper sleep stages.
The benefits of a cool room go far beyond better sleep. Cooler temperatures help your body tap into “brown fat,” a metabolically active tissue that burns white fat and improves insulin sensitivity. This can aid in weight management and reduce the risk of metabolic diseases like type 2 diabetes. Cooling down at night also promotes brain detoxification by enhancing slow-wave sleep, where harmful proteins like beta-amyloid—linked to Alzheimer’s—are flushed from the brain. Whether you’re managing menopause, struggling with insomnia, or simply looking to feel more refreshed, dialing down the thermostat could be your secret weapon for better health, sharper cognition, and deeper, more restorative sleep.