Dr. Kelvas would have you believe that maintaining a perfect temperature is the holy grail of sleep. When the room is either too hot or too cold, the body struggles with hormone regulation, making it hard to fall or stay asleep.

As Sleep Foundation recommends, the ideal room temperature sits between 60°F (15.5°C) and 68°F (20°C). This temperature sweet spot assists your body’s natural thermoregulatory process, promoting sleep latency (that blessed moment you drift off) and overall sleep quality.

Temperature and the Body

Your body’s amazing thermoregulatory magic keeps your internal temperature stable no matter how wild the weather gets outside. This involves sweating to cool down or shivering to warm up, plus managing blood flow to the skin.

Sweating is not just an inconvenient consequence of too much salsa dancing — it’s your body’s way of cooling off. When things heat up, your sweat glands kick into gear and help keep you from overheating.

On the flip side, shivering is your body’s somewhat irritating way of warming up. It’s like a built-in mini-workout regime, causing your muscles to contract and generate heat.

Let’s not forget vasodilation. When the blood vessels near your skin’s surface open up, it’s like cracking a window open in a stuffy room. Vasoconstriction is the opposite, making you feel snug as a bug by restricting blood flow and conserving heat.

You’ve likely experienced thermoregulation if you’ve ever covered your chilly feet with socks in bed or stuck them out from under the blanket when your body threatens to overheat.

Temperature and Sleep

Now let’s talk about how temperature waltzes with sleep. Throughout human evolution, external temperature cues have helped regulate our sleep-wake cycles. Researchers peeking into pre-industrial societies found people dozed off as evening temperatures dipped and woke up with the coldest point just before dawn.

About two hours before sleep, your core body temperature takes a nosedive, reaching its lowest during slow-wave sleep.

Dr. Valerie Cacho notes that while melatonin is usually linked with light exposure, cooler room temperatures can ramp up its production too. A too-warm room, on the other hand, might sabotage the rapid eye movement (REM) phase of sleep, where your brain is a rave party of activity, and slow-wave sleep (SWS), where soothing bodily recoveries occur. Dreaming happens in REM, while SWS helps the body’s healing processes.

Studies show that elderly men exposed to warmer bedroom temperatures had disrupted sleep, with less REM (which is linked to cognitive functions) and more wakefulness.

Also, warm-blooded animals, like ourselves, have lower body temperatures, supporting better REM sleep. High humidity? Bad news for sleep quality, too, as it prevents your body from dropping core temperature efficiently.

On the flip side, a room that’s too chilly means your body has to expend energy staying warm, keeping you from diving into deep sleep.

Benefits of Sleeping in a Cold Room

Remember the night sweats that left you feeling like a wrung-out dish rag? Keeping your room cool can help prevent those. Here’s how dialing down the thermostat works wonders.

Better Sleep Quality

A comfortably chilly room can help your body release just the right amount of melatonin and keep cortisol (the annoying stress hormone) in check, letting you stay in REM and slow-wave sleep longer. Sweet dreams with no night sweats!

Fall Asleep Faster

Lowering your core body temperature is key to falling asleep quicker. If you can fall asleep within 10–20 minutes, you’re doing splendidly. The trick to sleeping like a log? Let your body release that extra heat effortlessly.

Better Weight Management

Cold temperatures activate “brown fat,” the metabolically active tissue that burns the bad, white fat around your tummy. An Australian study found that men who slept in 66°F (18.8°C) environments doubled their brown fat volume in just a month.

Lower Risk of Diseases

More brown fat means better insulin sensitivity and reduced risk of type 2 diabetes. The Australian study showed cooler sleepers burning more calories daily. And cold room sleep may help stymie Alzheimer’s disease by enabling all restorative sleep stages and the recommended seven to nine hours of slumber.

So there you have it. Do you still think a warm room is the way to go? Think again! Embrace the cool and find yourself waking up refreshed and ready to conquer the day.