Does your body temperature rise when you sleep?

Updated October 7, 2026.

At night two parts of the body move in opposite directions, so this question gets two different answers online. The core cools from the evening on, while the hands and feet warm by about 1°C, just under two degrees Fahrenheit, around the moment of falling asleep, and that skin warming is how the core gets rid of its heat (smart bed skin temperature study).

Short answer: No, not at the core, which peaks in the early evening, falls further after bedtime and begins to climb again before you wake (study of younger and older women). The skin on your hands and feet warms to let that heat out, and a cool bedroom helps it along. Most US health pages give 60 to 67°F (Cleveland Clinic), but a home study of older adults found sleep was most restful between 68 and 77°F (Hebrew SeniorLife). Treat either range as a starting point and adjust one degree at a time.

This guide is for: anyone who wakes up hot, argues over the thermostat, or wants to know what the body does with heat at night.

Key Takeaways

Three findings carry most of this guide: which way core heat moves at night, which room range to try first, and what a warm bath does.

1. Your core cools at night while the skin of your hands and feet warms. Hands and feet warm by about 1°C as you fall asleep (smart bed skin temperature study). In lab work, that hand-and-foot warming predicted how quickly people fell asleep better than core temperature did (Kräuchi et al., 2000).
2. Start between 60 and 67°F, then adjust a degree at a time. Of the 12 health and sleep pages we read on September 26, 2026, 8 give exactly that range. Even so, home data on older adults found the most restful sleep between 68 and 77°F (Hebrew SeniorLife).
3. Warm up before bed so you cool down in it. A pooled review found that bathing 1 to 2 hours before bed in water of about 104 to 109°F improved sleep, and bathers fell asleep about 10 minutes sooner on average (UT Austin).

On This Page

Eight questions, in the order a restless night tends to raise them, from what the body does to what can change in the bedroom.

The first two sections explain what the body does with heat at night. The third and fourth put the published room ranges next to what we counted when we read a dozen pages of advice. The last four turn the research into choices about bedding, baths and fans. Every figure links to the page it came from, so each number can be checked against its source.

Does your body temperature go up or down during sleep?

Your core temperature goes down through the night and bottoms out a few hours before waking, while the skin on your hands and feet warms up.

Body heat follows a daily rhythm set by the brain's internal clock. Core temperature peaks in the early evening, falls further after bedtime and begins to rise again before you wake (study of younger and older women). Heat lost through the hands and feet shapes that rhythm, so their skin temperature runs in the opposite direction to the core (Scientific Reports, 2019).

Near sleep onset, hands and feet warm by about 1°C and the abdomen by about 0.5°C as more blood flows close to the surface (smart bed skin temperature study). In Fahrenheit that is just under two degrees at the extremities and about one at the belly, which is why a partner's feet can feel hot at bedtime even while their inner temperature is falling.

Sleep Foundation reports that babies whose temperature rhythm has matured reach a minimum core temperature of 97.5°F (36.4°C) within four hours of bedtime, a pattern it describes as similar to adults (Sleep Foundation).

Why do your hands and feet get warm as you fall asleep?

Warm hands and feet are the body's radiators: widened blood vessels near the skin let core heat escape, and that escape helps sleep begin.

In a controlled study, researchers compared several body signals against how long people took to fall asleep. The warming gap between the hands and feet and the trunk was the best predictor of how long people took to fall asleep. It beat core temperature, heart rate, melatonin timing and how sleepy people said they felt (Kräuchi et al., 2000). The authors took this as evidence that losing heat through the hands and feet speeds the start of sleep.

That helps explain an old habit. In a Korean study held in a room at 23°C, a typical indoor setting, bed socks kept feet about 2.3°F (1.3°C) warmer. With socks on, people fell asleep 7.5 minutes sooner and slept 32 minutes longer than without them, and core temperature did not differ between the two nights (Ko and Lee, 2018).

Treat that result with caution, because the trial enrolled six young men for two nights each (Ko and Lee, 2018), far too few to predict what socks will do for any one sleeper. What it does show is the mechanism at work: warm feet in a cool room let heat out without warming the core.

If a sleeper's feet are icy at lights-out, the blood vessels in them have narrowed and the heat has nowhere to go. Socks, a warm footbath or a hot water bottle at the foot of the bed deal with that directly. Leaving the thermostat where it is lets the core keep dropping the way it should.

What temperature should your bedroom be for sleep?

For most adults, start between 60 and 67°F, the range most US health pages give, and move a degree at a time until you stop waking up.

The most quoted range comes from clinicians. Cleveland Clinic's sleep psychologist gives 60 to 67°F (15 to 19°C) for adults and compares a good bedroom to a cave: cool, dark and quiet (Cleveland Clinic). Sleep Foundation runs slightly warmer. It says most doctors recommend 65 to 68°F (15.6 to 20°C) and names about 65°F as a middle value (Sleep Foundation).

Children run warmer, and Cleveland Clinic puts babies and toddlers at 65 to 70°F. Sleep Foundation adds that a bedroom that is too warm may raise the risk of sudden infant death syndrome, so a nursery should be warm but never hot.

Pick a starting number from the row that fits the sleeper and hold it for a week, then move one degree and compare how you sleep. Temperature is only one part of the cave. Our guides to blackout curtains and blackout shades cover the dark part.

Where does the 60 to 67 degree advice come from?

We read 12 published pages that give a bedroom figure. Eight repeat 60 to 67°F exactly, three go higher, and one stops lower, at 65°F.

We read 12 pages on September 26, 2026 that each state a bedroom temperature for adults. Four further pages, from companies that sell mattresses or bed-cooling products, were set aside and are not among the 12. The 12 we counted came from health publishers, sleep sites, a fitness company's blog and heating and cooling companies, and each went into one of three buckets according to the range it states.

Two things stand out, and the first is that the agreement is broad but thin. Sleep.com and Superpower, for example, use the same Celsius conversion, 15.5 to 19.4°C, which suggests the figure is being passed from page to page. Also, only 3 of the 12 ranges reach 68°F, the bottom of the band where older adults slept most restfully at home, and none reaches that band's 77°F top. For a younger adult the common range is a fair start, but for an older one it may run a few degrees cool.

Is a cold room better for sleep than a warm one?

A cool room with enough bedding beats a warm one. Heat cuts deep and dream sleep; cold under covers mostly shifts heart rhythm instead.

In the lab, heat and cold pushed far enough do the same damage: they increase wakefulness and cut rapid eye movement and slow wave sleep, the dream and deep stages (Okamoto-Mizuno and Mizuno, 2012). Without covers, cold disturbs sleep stages more than heat does. Real bedrooms have covers, and that flips the picture. With bedding and clothing in use, the review found that heat still raised wakefulness and cut deep and dream sleep, humid heat added to the disruption, and cold left sleep stages alone.

Cold still has a cost: the same review reports that it changed the heart's automatic responses during sleep even when sleep stages and comfort ratings stayed the same, and the authors called for more research on it.

The cost of heat shows up across whole populations. One team linked more than 7 million sleep records from 47,628 people in 68 countries to local weather and found that warmer nights shortened sleep (Minor et al., 2022). Reporting on the study, Gulf News put the loss at an average of 44 hours of sleep a year in the first two decades of this century (Gulf News).

Cooling the body itself may deepen sleep. In a 72-person study using a mattress with high heat capacity, deep sleep rose by 7.5 minutes a night and heart rate fell by 2.36 beats per minute (Scientific Reports, 2024).

If you sleep in a cold room, the rule is to keep the air cool and the bedding warm, and to treat a hot, humid room as the bigger threat.

Do older adults need a warmer bedroom at night?

Possibly: in one year-long home study of older adults, sleep was most restful between 68 and 77°F, a few degrees warmer than the usual advice.

The one long home study of older sleepers we found points warmer than the usual range. Researchers put temperature sensors in the bedrooms of older adults and tracked their sleep with wearable monitors over 12 months (Mather Institute).

Sleep was most efficient and restful between 68 and 77°F, and efficiency dropped by 5 to 10% as the room warmed from 77 to 86°F (Hebrew SeniorLife). The authors also found large differences in the best temperature from one person to the next.

Why might older sleepers differ? In a small metabolic-chamber study, women with an average age of 72 had higher core and hand-and-foot temperatures during sleep than women averaging 23. The authors say the smaller nighttime core drop in older people is still unexplained (study of younger and older women). The global wristband study adds that the sleep lost to warm nights was substantially larger for older adults and for women (ScienceDaily, 2022).

Our reading is that an older sleeper can reasonably start with the room a few degrees above the usual range. If the bedroom climbs into the 80s on summer nights, it needs a fan or air conditioning, not just a thinner sheet.

Why do you wake up hot in the middle of the night?

Usually the room or the bedding is holding heat your skin is trying to shed, and humid air or hormone shifts can add to that load.

Under the covers a sleeper lies inside a small climate of their own. Researchers describe the layer of air next to the skin in bed as sitting at 31 to 35°C, roughly the high eighties to mid nineties in Fahrenheit, warm enough to carry heat out through the hands and feet (Scientific Reports, 2024). When that layer gets too hot or too damp, the core cannot shed heat, and sleep breaks.

Humidity matters as much as the thermostat setting does. The 2012 review found that humid heat adds to the thermal load of sleep and disturbs sleep stages further (Okamoto-Mizuno and Mizuno, 2012). That is why a muggy summer night can wake a sleeper at a thermostat setting that feels fine in winter.

Hormones shift the baseline too: in nine young women studied in a metabolic chamber, the second half of the menstrual cycle raised average core temperature by 0.27°C, about half a degree Fahrenheit, and held back heat loss during the first 2 hours of sleep (menstrual cycle study).

If you keep waking hot in a cool room, check the bed before the thermostat, because a heavy comforter or synthetic pajamas can trap heat against the skin. Night sweats that soak the sheets in a cool room are worth raising with a doctor, since the cause may have nothing to do with the bedroom.

How can you cool your body down before bed?

Warm up first: a bath or shower at 104 to 109°F taken 1 to 2 hours before bed is linked with falling asleep sooner and sleeping better.

A pooled review of earlier studies found that bathing 1 to 2 hours before bed in water of about 104 to 109°F improved overall sleep quality, and it cut the time to fall asleep by an average of 10 minutes (UT Austin). The researchers think warm water draws blood to the hands and feet, which then lets body heat escape faster (Sleep Foundation). The lead author told CNN that the one-to-two-hour window is the sweet spot and that a bath 15 minutes before bed is too soon (CNN, 2019).

The table below lists each approach in this guide with our own judgement of how much weight its evidence can bear.

Common questions

Short answers to the questions people often ask about room temperature, baths, fans and cold feet, each drawn from the sources above.

What is the best temperature to sleep in?

For most adults the usual starting range is 60 to 67°F (Cleveland Clinic). Sleep Foundation gives 65 to 68°F, and older adults may sleep better a few degrees warmer.

Is 72 degrees too warm to sleep?

It is above the range most health pages give, but it sits inside the 68 to 77°F band where older adults slept most restfully in one home study, so if you sleep well at 72°F, keep it.

Does a cold shower before bed help you sleep?

Probably not, according to the lead author of the bath review, who told CNN that a cold shower makes the body warm itself back up, which makes sleep harder (CNN, 2019).

How long before bed should you take a warm bath?

Aim for one to two hours before bed, the window that produced faster sleep onset in the pooled review, since a bath taken 15 minutes before bed comes too soon for the same benefit.

Should you sleep with a fan on?

Yes, if you cannot cool the room any other way. A sleep psychologist quoted by Peloton suggests fans when you lack air conditioning. The steady hum also masks noise, which our white noise guide covers.

Why are my feet cold when the rest of me feels hot?

Cold feet mean the blood vessels in them have narrowed, so heat stays trapped in the core. Socks or a warm footbath open those vessels, which is why the socks study found faster sleep without a warmer core.