What's the absolute best bedroom temperature for sleep?

For most healthy adults, 60–67°F (15.5–19.5°C), with 65°F (18.3°C) considered the centre of the sweet spot. This is the range supported by the Sleep Foundation, the American Sleep Association, Cleveland Clinic, and most peer-reviewed sleep research published in the last decade. Personal preference shifts the exact number within that band, but 70°F+ is consistently associated with fragmented sleep in the literature.

Is 68°F too warm to sleep in?

It's right at the edge. 68°F is technically within the range that some guidelines (like the Sleep Charity UK) consider acceptable, but multiple recent studies show measurable reductions in deep sleep and REM above 67°F. If you sleep hot, are over 40, or use a memory foam mattress that traps heat, dropping from 68°F to 65°F often makes a noticeable difference.

Should babies and older adults sleep at a different temperature than 60–67°F?

Yes. Infants need a warmer room — the American Academy of Pediatrics recommends 68–72°F (20–22°C) to reduce SIDS risk while keeping them comfortable. Older adults often sleep more efficiently between 68–77°F (20–25°C) because age-related changes in circulation and skin thickness make them more vulnerable to feeling cold. The 60–67°F range is specifically for healthy adults under roughly 65.

Why do I sleep better when the room is cold?

Because your core body temperature has to drop roughly 1–2°F to initiate and maintain deep sleep. A cool bedroom helps that drop happen passively, without your body fighting against the environment. People who sleep best in cold rooms are usually responding to the same underlying physiology — they just need a bigger temperature gradient to dump heat efficiently.

My partner and I prefer different temperatures. What's the compromise?

Set the room to the cooler partner's preference, and have the warmer partner layer up with a thicker duvet, wool socks, or a heated mattress pad on their side. It's far easier to add warmth to one body than to lower a whole room's air temperature without making the cool sleeper miserable. Dual-zone mattress covers exist if both of you sleep hot or cold differently.

The Best Bedroom Temperature for Sleep: What 2025 Research Actually Says (and How to Hit It)

The optimal bedroom temperature for healthy adult sleep is 60–67°F (15.5–19.5°C), with 65°F (18.3°C) sitting at the centre of the sweet spot. That number isn’t a marketing claim — it’s the figure that has held up across decades of polysomnography studies, the latest published in 2025. Below it, your body works to keep itself warm. Above it, your body works to dump heat. In between, your physiology gets out of its own way and lets you sleep.

The harder question isn’t what temperature is best. It’s why, how much it changes with age and gender, and how to actually hit that number given the realities of HVAC, partners, and the fact that most bedrooms are quietly running 5–10°F too warm. This guide walks through all of it.

Why this specific range — the thermoregulation mechanism

Your core body temperature naturally drops between 1 and 2°F as you transition into sleep, and stays low through the night until about 90 minutes before you naturally wake. That nocturnal cooling cycle is one of the strongest biological signals your brain uses to initiate sleep onset and to gate access to the deeper sleep stages.

If your bedroom is too warm, two things happen. First, the initial drop is harder to achieve, which is why sleep onset gets longer in hot rooms. Second, your body cycles up into lighter sleep stages more often through the night to try to dump heat — which is why hot sleepers wake more around 3am, often soaked. A 2024 study in Scientific Reports showed that even modest improvements in conductive heat loss during sleep increased measured slow-wave (deep) sleep and reduced heart rate variability.

The 60–67°F band exists because it’s the range that allows the natural drop to happen passively without making you cold enough to wake.

The 2025 research: gender differences, REM, and deep sleep

A study published in PMC in 2025 (Polysomnographic Evidence of Enhanced Sleep Quality with Adaptive Thermal Regulation) added something the older literature largely missed: men and women don’t get exactly the same benefit from cool sleeping conditions.

When the room was kept in an adaptive cool range, the study found:

Men saw a significant increase in REM sleep percentage (around 20.8%)
Women saw a significant increase in deep sleep percentage (around 12.3%)

Both groups improved overall sleep quality on objective measures, but the type of improvement diverged. This matches earlier observations that female thermoregulation is influenced by cyclic hormonal patterns, while male thermoregulation is comparatively flatter.

The practical implication is small but useful: a man relying on REM sleep for cognitive recovery and a woman relying on deep sleep for physical restoration are both helped by the same 60–67°F range, but they’re being helped through slightly different sleep-architecture mechanisms. The advice is the same; the reason it works varies a little.

A separate December 2025 preprint on cooling interventions for sleep reviewed the broader mechanism and concluded that thermoregulation is “central to both sleep initiation and maintenance,” with cooling interventions showing measurable benefit for insomnia, anxiety-related sleep disturbance, and conditions involving impaired vasodilation.

Best bedroom temperature by age

The 60–67°F figure is specifically for healthy adults. Other age groups have meaningfully different physiology, and using the adult target on an infant or an elderly relative can produce the opposite of the intended effect.

Age group	Recommended bedroom temperature	Why it shifts
Newborns & infants (0–12 mo)	68–72°F (20–22°C)	High surface-to-mass ratio means rapid heat loss; SIDS risk rises in colder rooms
Toddlers (1–3 yr)	65–70°F (18–21°C)	Still developing thermoregulation; slightly warmer than adult
Children & teens (4–17 yr)	60–67°F (15.5–19.5°C)	Adult range; can typically use the same setting
Healthy adults (18–64 yr)	60–67°F (15.5–19.5°C)	The core focus of this guide
Older adults (65+ yr)	68–77°F (20–25°C)	Slower circulation, thinner skin, reduced shivering response; some 2023 research shows sleep efficiency peaks in this warmer band

Source guidance: the American Academy of Pediatrics for infants, the Sleep Foundation and Cleveland Clinic for adults, and 2023 research on older adults summarised by the Sleep Foundation’s bedroom environment guide.

The temperature zones, visually

The same range mapped onto a usable scale — the green band is where sleep architecture is most consistently supported, and the red band is where most people start to sweat, wake fragmented, or both.

💡 Not sure if temperature is the actual bottleneck for your sleep, or just one of several factors?

👉 Take the 60-second Sleep Quiz → — 7 questions that identify the most likely root cause.

Why most bedrooms are too warm

Most centrally-heated North American homes default to somewhere between 68 and 72°F overnight. That’s a heating-engineering compromise designed to keep the entire house tolerable, not a sleep-optimisation setting. The result is that the average bedroom is running 3–7°F above where the sleep research consistently shows benefit.

Adding to that:

Memory foam mattresses trap heat, often pushing the bed surface temperature 5°F above the ambient air.
Polyester and microfibre bedding prevents moisture-driven cooling.
Closed curtains plus a partner can raise the air around the bed by 2–3°F over the course of the night, even if the thermostat is correct.

Put together, a bedroom set to a “reasonable” 70°F can deliver a bed surface temperature in the high 70s. That’s well into the disrupted-sleep zone for most adults.

My personal protocol — what works for me

When I tracked seven sleep variables every night for four months in 2023, bedroom temperature was the single strongest predictor in my data. Nights when my room was 70°F or warmer produced longer sleep onset, more 3am wake-ups, and more morning sweating. Nights when it was 65°F or cooler produced the opposite, almost cleanly.

My protocol now, after four years of testing, is:

Thermostat at 65°F year-round from one hour before bed through 30 minutes before my alarm.
A small box fan on low at the foot of the bed for white noise and gentle air movement, even in winter.
Percale cotton sheets in summer, bamboo lyocell in shoulder seasons, and a single wool blanket layer I can pull on or off without waking.
A wool mattress topper over my main mattress to break up the heat-trapping effect of the foam.
No second person in the room is not always practical — but I’ve learned that if my partner is in bed, I move the thermostat one degree lower to compensate.

This setting wouldn’t have suited my grandmother, who was 86 and chronically cold. It probably wouldn’t suit a 4-month-old. But for a 46-year-old in reasonable health, it has been the difference between fragmented and consolidated sleep.

How to actually hit 60–67°F

This is where most articles handwave. Knowing the number isn’t useful if your HVAC can’t deliver it. Here’s the practical menu, cheapest first.

If you control your thermostat

Set it to 65°F for the sleeping hours specifically (most modern thermostats support schedules). You don’t need the whole house this cool — just the bedroom during sleep. If you have zoned heating/cooling, use it.

If your AC can’t go that low

Run a fan or two — directional fans pointed across the bed beat fans pointed at the wall. A box fan in a window pulling cool night air in is one of the best low-cost interventions on hot nights, and free during shoulder seasons.

If the room is structurally hot (top floor, west-facing windows)

Address the heat source before chasing it with air conditioning:

Blackout curtains rated for thermal performance
Close west-facing blinds in the late afternoon
A through-the-wall AC unit or a portable AC vented through a window

If your mattress traps heat

This is often the bigger issue than air temperature. A foam mattress in a 65°F room can still deliver a 75°F sleep surface. Options:

Switch to a percale or bamboo lyocell top sheet (free if you already own them)
Add a wool or cotton mattress topper (modest cost, significant impact)
Use a phase-change material (PCM) cooling topper — peer-reviewed evidence in 2024–2025 shows these can drop bed surface temperature by up to 5°F vs untreated foam
Replace the mattress with a hybrid (coil-and-foam) for permanent airflow

🛏 If you suspect your mattress is part of why you can’t hit the right sleep temperature, my Mattress & Pillow Firmness Finder → matches you to options that fit your weight, sleep position, and temperature profile in under 60 seconds.

Summer vs winter strategy

The right room temperature doesn’t change much between summer and winter — but the way you get there does.

In summer, the challenge is dumping heat. AC, fans, cooling toppers, and stripping back to a single light layer all do work here. Avoid synthetic bedding entirely.

In winter, the challenge is overshooting. Central heating set to keep the rest of the house comfortable will often push the bedroom into the 70s. Either schedule the heat down at night, close the bedroom vents, or rely on heavier duvets at a colder ambient temperature.

The constant is the same: 60–67°F ambient, with bedding adjusted to keep the bed comfortable.

When ambient temperature alone isn’t enough

For some people, getting the bedroom to 65°F doesn’t solve their sleep problems. That usually points to one of three things:

Mattress and bedding are the bottleneck, not the air — addressable with toppers, sheets, and material upgrades
The body’s thermoregulation is disrupted — perimenopause, hyperthyroidism, anxiety, certain medications. These usually need a medical conversation, not a thermostat adjustment
An underlying sleep disorder — sleep apnea, restless leg syndrome, chronic insomnia. CBT-I and sleep studies are appropriate next steps

Medical disclaimer: I’m not a physician, sleep therapist, or licensed medical professional of any kind. SleepNestGuide is an informational resource and does not constitute medical advice. The diagnostic tools on this site identify likely physical contributors to sleep quality — they do not diagnose medical conditions.

The bottom line

For most healthy adults, 60–67°F (15.5–19.5°C) is where the sleep architecture, the cardiovascular benefit, and the comfort all converge. The 2025 research strengthens that conclusion rather than challenging it — but adds useful nuance about how the benefit lands differently for men and women, and how older adults need a warmer setting.

The harder part is achieving it. If you’ve never measured your actual bedroom temperature at 3am, that’s the first thing to do. A $10 digital thermometer near the bed for a week will tell you whether you have a temperature problem, a mattress problem, or both.

🌙 Take the Free Sleep Quiz →

7 questions. No email required. Personalised result with product matches.

Affiliate disclosure: SleepNestGuide participates in Amazon Associates and other affiliate programmes. Product recommendations surfaced from my diagnostic tools may earn me a small commission at no additional cost to you. Recommendations are based on specification match to your sleep profile — not commission rates.