Why Do I Get So Hot When I Sleep? 11 Ways to Cool Down

You may get hot when you sleep due to a warm bedroom, thick pajamas, hormones, or poor sleep hygiene like exercising or having caffeine too late in the day.
Published
2023-05-04
19 MINS
Written by
Jeff Kahn, M.S., Rise Science Co-Founder
Reviewed by
Chester Wu, MD, Rise Science Medical Reviewer
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We bring sleep research out of the lab and into your life. Every post begins with peer-reviewed studies — not third-party sources — to make sure we only share advice that can be defended to a room full of sleep scientists.
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Updated Regularly
We regularly update our articles to explain the latest research and shifts in scientific consensus in a simple and actionable way.

Why do I get so hot when I sleep?

  • You may get hot when you sleep due to a warm bedroom, thick pajamas, hormones, or poor sleep hygiene like exercising or having caffeine too late in the day.
  • To stop getting hot at night, try using a fan or air conditioning to cool down your bedroom (aim for around 65 to 68 degrees Fahrenheit), take a warm shower or bath before bed, and avoid night sweat triggers like caffeine and alcohol. If you’re still feeling too hot at night, reach out to your healthcare provider.
  • The RISE app can guide you through 20+ sleep hygiene habits to help you fall asleep faster, wake up less often throughout the night, and reduce the chances of anything hiking your body temperature when you’re trying to drift off.

Feeling cozy under the covers at night is one thing. But feeling sweaty, sticky, and disgustingly warm is a whole new ball game. And feeling hot at night isn’t just uncomfortable, it can stop you from falling asleep or wake you up during the night. 

This leaves you both sweaty and sleep deprived — not what you need to feel your best each day. 

To make matters worse, a warm bedroom isn’t the only culprit behind feeling hot at night. This can make cooling down and fixing the issue a little tricky. But there are some solutions that can improve your nighttime temperature, sleep, and next-day energy levels.

Below, we’ll dive into why you get so hot at night and how you can stop it from happening. Plus, we’ll share how the RISE app can guide you through sleep hygiene behaviors that can help your body regulate its temperature, so you can get a good night of sweat-free sleep.  

Advice from a sleep doctor:

“Feeling too hot when you sleep is not only uncomfortable, it can make it harder to fall asleep. Try using a fan or air conditioning to cool down your bedroom, taking a warm shower or bath before bed, and avoiding night sweat triggers like caffeine and alcohol. If you’re still feeling too hot at night, reach out to your healthcare provider.”

Rise Science Medical Reviewer Dr. Chester Wu

Why is My Body Hot While Sleeping?

Feeling too warm in bed? Here’s what could be to blame. 

1. Your Bedroom is Too Hot or Humid

RISE app screenshot showing when to check sleep environment
The RISE app can remind you to check your sleep environment before bed.

One obvious reason you feel too hot at night is that your bedroom is too hot. And beyond making you feel warm, this can be disruptful to your sleep.  

You need a drop in body temperature to fall asleep and get the best sleep possible (more on the science behind this soon). If your bedroom is too warm, either from hot weather or central heating, it’s going to interfere with your body’s ability to cool down for sleep. 

One study found when participants slept with a high blanket temperature, which caused them to have a body temperature of about 37 degrees Celsius, which is about 99 degrees Fahrenheit, they had: 

  • Less sleep overall 
  • More frequent and longer awakenings 
  • Greater shifting among sleep stages
  • Less deep sleep and less REM sleep 

Humidity also comes into play. While some studies say heat plays more of a role in disturbing sleep, other research shows humid heat further increases wakefulness and decreases rapid-eye-movement sleep (or REM) and deep sleep compared to heat. Humidity can also suppress the decrease in core body temperature needed to fall asleep.  

More research needs to be done to find the perfect sleep temperature. Research from 2019 states the optimal room temperature is about 19 to 21 degrees Celsius, or 66 to 70 degrees Fahrenheit. But other research points to 65 to 68 degrees Fahrenheit as being the ideal temperature range for sleep. 

RISE can remind you to check your sleep environment before you head to bed, so you’ve got time to cool your bedroom down before you try to fall asleep.

RISE users on iOS 1.202 and above can click here to set up their check environment habit reminder.

2. Your Bedding and Pajamas are Too Thick 

Your room may be the ideal temperature, but if you’re wrapped up in thick bedding, sheets with a high thread count, or wearing fluffy pajamas, your body may struggle to cool down. 

Thick bedding and sleepwear can trap heat, especially if you’re using and wearing the same ones in the winter and summer months. 

Your mattress can also be to blame. Memory foam mattresses, for example, trap heat more than spring mattresses. 

3. You’ve Exercised Too Close to Bedtime

RISE app screenshot showing when to do your workouts
The RISE app can tell you when to avoid exercise before bed.

Exercise in general is good for your sleep, but working out intensely within an hour of bedtime can keep you up and make you feel warm. The workout increases your body temperature, which can override the drop in body temperature you need to drift off. 

In general, you should avoid vigorous physical activity within an hour of bedtime. 

We’ve covered more on the best time to work out here, and why you should avoid the run-up to bedtime.

RISE can tell you when to avoid exercise each day to stop it from disrupting your sleep and hiking your body temperature before bed. 

RISE users on iOS 1.202 and above can click here to set up their avoid late workouts reminder.

4. You’ve Had Too Much Caffeine 

Having a cup (or two) of coffee in the afternoon can keep you up at night in more ways than one. It’s not just the caffeine in your system that messes with your sleep. 

Research shows caffeine is linked to a higher core body temperature. In this study, participants were given 2.9 milligrams of caffeine per kilogram of body weight, which is equivalent to about 200 milligrams (or two espressos) for a 70-kilogram (154 pound) adult. This much caffeine five hours before bed was linked to a higher core body temperature when participants tried to sleep.

So, if you’ve had too much coffee, or caffeine too late in the day, you may be left wide awake at bedtime and warmer than usual.

You don’t have to give up coffee altogether, though. We’ve covered how much caffeine is too much here and when you should stop drinking coffee here. 

And RISE can also tell you when to have your final cup of coffee each day. 

RISE users on iOS 1.202 and above can click here to set up their limit caffeine reminder.

5. You’re Stressed or Anxious 

Stress and anxiety can raise your overall body temperature and trigger hot flashes. 

Both chronic and acute stress can impact your temperature, too. So a stressful day or few weeks could leave you sweating at night, or a stressful experience before bed (checking work emails or having anxious thoughts as you try to fall asleep) could be to blame, too. 

When you’re stressed, your body releases the hormones cortisol and adrenaline, which prime your body for danger. This increases your heart rate and circulation and leaves you feeling warmer than usual. 

Stress in the middle of the night can also make you hot and sweaty. This could be from a nightmare or from a sleep apnea episode — which is when your breathing cuts off temporarily and your brain jolts you awake to get some oxygen.

If anxious thoughts are contributing to feeling warm and worried before bed, we’ve covered how to sleep with anxiety here. 

6. You’re Sharing Your Bed

Cuddling up to your partner at night may feel relaxing, but it can also leave you both feeling too warm to sleep. You’ll feel your partner’s body heat and the combined body heat may get trapped under the covers, too. The same goes for any pets you share a bed with. 

Or it may be down to your partner simply liking thicker blankets or a warmer bedroom than you. 

7. Your Hormones Are to Blame 

Changing hormone levels can leave you with a higher body temperature than usual, and feeling hot and sweaty. 

These fluctuations can come from: 

  • Your menstrual cycle: Body temperature levels are higher during the luteal phase (after ovulation and before your period) than they are during the follicular phase (which includes your period and the time before ovulation). 
  • Pregnancy: Beyond hormonal changes, you’ll have more blood in your body when pregnant, which can up your body temperature. 
  • Menopause and perimenopause: Declining estrogen has been linked to hot flushes, a common menopause symptom. 
  • Low testosterone: This can trigger night sweats. Low testosterone can be caused by aging, obesity, and sleep deprivation. 

8. You’re Battling an Illness  

Illnesses can lead to an increase in body temperature or cause a fever. This may be temporary and you’ll just feel extra hot at night as your body fights off the illness. 

Illnesses that may be to blame include: 

  • The common cold
  • Flu
  • COVID
  • Strep throat 
  • Bacterial infections 
  • Pneumonia 

9. It’s a Side Effect of Medication 

Certain medications can increase your body temperature, including: 

  • Painkillers like aspirin 
  • Diabetes medications 
  • Steroids
  • Hormone therapy meds 
  • Antidepressants 

Speak to your healthcare provider if you think your medication could be to blame.

10. It’s a Medical Condition 

Certain medical conditions can leave you too warm at night, too. 

These include: 

  • Hypoglycemia (low blood sugar)
  • Hyperthyroidism (overactive thyroid)
  • Sleep apnea
  • Hyperhidrosis (chronic sweating)
  • Coronary heart disease
  • Cancer 

11. You’ve Got Night Sweats 

There’s a difference between feeling warm and sweating at night and having night sweats. While there’s no set definition, many experts define night sweats as sweating so much you need to change your bedding or sweating even when your bedroom isn’t warm. 

Night sweats can be caused by many of the same things that can make you warm at night, including: 

  • Stress and anxiety 
  • Alcohol 
  • Spicy foods 
  • Pregnancy 
  • Menopause
  • Medications — like antidepressants, painkillers, and diabetes medications 
  • Medical conditions — like hypoglycemia, hyperthyroidism, and sleep apnea  

Think you’ve got full-blown night sweats? You can learn more about the causes of night sweats here and when to be concerned about night sweats here.

Why is Temperature Important for Sleep?

Excessive sweating at night is obviously not going to feel great and this uncomfortable feeling may keep you up. But temperature and sleep are more tightly linked than that. 

Your body temperature is, obviously, affected by the outside world — a hot room will leave you feeling hot. But body temperature also fluctuates to its own rhythm throughout the day and night.

It’ll be at its highest around 6 p.m. and at its lowest at around 4 a.m — although the exact timing will depend on your chronotype, or whether you’re a natural morning or evening person. 

This is part of your circadian rhythm, your body’s roughly 24-hour internal clock. As well as body temperature fluctuations, your circadian rhythm dictates your sleep-wake cycle and production of certain hormones.

About two hours before bedtime, your body begins to naturally cool as it gets cooler outside. This is a signal to your body that it’s time to start getting ready to sleep.  

Research shows your alertness levels fall as your core body temperature falls. And you’re most likely to fall asleep when your body temperature is at its steepest rate of decline. 

When you transition from wakefulness to sleep, your body temperature drops by about one to two degrees Fahrenheit. And it continues to decrease after you’ve fallen asleep. 

If you’re too hot for whatever reason, your body temperature won’t drop — or drop enough — and your body won’t produce as much melatonin, your natural sleep hormone. This can make it harder to fall asleep. 

Being too hot can interfere with your shut-eye even after you’ve fallen asleep, too, as heat exposure can decrease deep sleep and REM sleep. 

You don’t want to be too hot, but you also don’t want to be too cold, either. Cold exposure while sleeping can change your cardiac autonomic activity, which includes your heart rate, and it can make it harder to get up in the morning as it reduces how much cortisol your body makes, which helps you feel alert.  

How Do I Stop My Body from Being Hot When I Sleep?

Now you know why you might be feeling hot at night, here’s how to cool down and get a good night’s sleep. 

1. Keep Your Bedroom Cool 

The first step to staying cool at night is making sure your bedroom isn’t too warm. While there’s no set temperature, aim for around 65 to 68 degrees Fahrenheit. 

Set your thermostat or turn on a ceiling fan, if needed. Some people even sleep better with the white noise from a fan. 

You can also open the window to cool down your bedroom. Research shows simply opening your window and internal bedroom door can lower the temperature, and therefore help to improve your sleep.

Just be sure opening a window doesn’t mean outside noise or air pollution keeps you awake. We’ve covered the best sleep sounds here and advice on keeping your room quiet (a good pair of earplugs can go a long way). 

While there is some science behind the perfect temperature for sleep, it can also come down to personal preference. 

Temperature preferences and needs may change between sexes and with age, too. For example, research shows women tend to choose bedding with a higher thermal resistance (more resistance to heat transfer) than men. And studies suggest sleep may be more affected by temperature as we age. 

So, you may need to tweak your bedroom temperature or open and close your window as you age, as well as throughout the year or when you’re ill, for example. 

2. Switch Up Your Bedding, Pajamas, and Mattress 

To help you cool down, try using fewer blankets or a thinner duvet, and go for natural fabrics like cotton, silk, and linen, which are more breathable. 

You can also wear lightweight pajamas in breathable fabrics like cotton, or simply skip nightwear altogether.  

When it comes to mattresses, spring or gel mattresses provide better airflow and retain less heat than all-foam mattresses. We’ve covered more on the best mattress for overheating here.

And if you’re still struggling with temperature regulation, you can buy special cooling pillows, a cooling mattress, or cooling sheets. 

If you and your partner like different temperatures, try sleeping with separate blankets, so you can choose your own thickness and materials. 

3. Improve Your Sleep Hygiene

RISE app screenshot showing when to limit caffeine intake
The RISE app can tell you when to do 20+ sleep hygiene habits.

Sleep hygiene is the name for the set of daily habits you can do to get the best night’s sleep possible.

Other than making sure your room isn’t too hot, improving your sleep hygiene is our number one piece of advice when it comes to cooling down at night. This is because it fixes many of the common culprits of overheating, such as anxiety or having caffeine and exercising too late in the day.

Good sleep hygiene also helps you fall asleep faster and wake up less often through the night, so you’ll be awake for less time suffering from the heat. 

And even if you’re hot because of something that’s hard to solve — like menopause or a medical condition — good sleep hygiene will make sure nothing else gets in the way of your sleep. 

Here’s what to do: 

  • Get bright light first thing: Light in the morning resets your circadian rhythm for the day, making sure you feel sleepy come bedtime. Aim for at least 10 minutes of light as soon as possible after waking up, or 15 to 20 minutes if it's overcast or you’re getting light through a window. 
  • Avoid light close to bedtime: Light suppresses the sleep hormone melatonin, so you want to avoid it in the run-up to bedtime. Dim the lights and put on blue-light blocking glasses about 90 minutes before bed (we recommend these). If you like to indulge in screen time before bed, we’ve covered how you can do this without impacting your sleep too much here.
  • Avoid caffeine, large meals, intense exercise, and alcohol too late in the day: These common sleep disruptors can keep you up or wake you up during the night. They can also contribute to you feeling warm at bedtime or trigger night sweats. RISE can tell you when to avoid each one daily. 
  • Do a calming bedtime routine: This is especially useful if stress and anxiety are contributing to you feeling warm. Try reading, listening to music, journaling, or doing yoga before bed. You can also try breathing exercises before bed or RISE’s audio guides on relaxation techniques for better sleep
  • Keep your bedroom dark, cool, and quiet: Once you’ve set your bedroom temperature, don’t forget that light and sound can disrupt your sleep, too. Invest in blackout curtains and wear earplugs and an eye mask

To stay on top of everything, RISE can guide you through 20+ sleep hygiene habits each day and tell you when to do each one to make them more effective.

RISE users on iOS 1.202 and above can click here to set up their 20+ in-app habit notifications.

4. Take a Warm Shower or Bath Before Bed

A warm shower or bath isn’t just a relaxing pre-bed activity, it can help your body cool down to drift off. 

Research shows hot water can decrease sleep latency (how long it takes to fall asleep). And having this bath or shower between one and eight hours before bed can increase slow-wave sleep (also known as deep sleep), and increase non-rapid-eye-movement sleep consolidation, meaning you wake up less often. 

It sounds counterintuitive, but warm water can actually help your body temperature drop. The heat opens up blood vessels on the surface of your skin, so body heat is lost more quickly and your core body temperature cools down. 

This is especially powerful when blood vessels open in your hands and feet, also known as distal vasodilation. Blood moves to your extremities, body heat is lost, and this cools down your core body temperature more quickly.  

A 2019 systematic review and meta-analysis found warm water of 40 to 42.5 degrees Celsius (104 to 108.5 degrees Fahrenheit) was associated with improved self-rated sleep quality and sleep efficiency (the time you spent in bed actually sleeping). 

It doesn’t need to be a long bath, either. When taken one to two hours before bed, a warm bath or shower for as little as 10 minutes was associated with “significant shortening” of sleep onset latency. 

5. Take a Footbath 

Don’t want to take a full bath or shower? A footbath can also help cool you down for sleep. 

A 2023 study found immersing just your feet in warm water can lead to an increase in skin temperature, but a decrease in core body temperature. The optimal temperature was 42 degrees Celsius, or about 108 degrees Fahrenheit, for 24 minutes. 

Footbaths may even help groups for whom sleep is challenging. For example, a 2020 study found footbaths improved the sleep quality of menopausal women, and a 2013 study found they helped elderly people improve their sleep quality and get more sleep overall. 

There’s no set definition for sleep quality yet, but the research into foot baths is promising. 

6. Wear Socks at Night 

One easy way to warm up your feet and therefore cool down your core body temperature? Wear socks at night. 

A 2018 study found wearing socks at night leads to: 

  • Falling asleep faster
  • Getting more sleep overall 
  • Waking up less frequently throughout the night 
  • Having a higher sleep efficiency 

We’ve covered more on the science behind why sleeping with socks on may help you fall asleep here, including which socks are best.

When to Be Concerned About Being Hot When You Sleep?

Meeting your sleep need — the genetically determined amount of sleep you need each night — is vital for high energy levels, a good mood, and maximum physical and mental health. 

So, while a one-off hot night is nothing to worry about, you don’t want being warm at night to regularly get in the way of you meeting your sleep need and start impacting your daily life. 

If you’re often feeling too warm at night, and improving your sleep hygiene and cooling down your bedroom hasn’t helped, speak to a healthcare professional to rule out an underlying health issue. 

You should also speak to a doctor if you experience night sweats and:

  • A fever 
  • Chills 
  • A cough 
  • Diarrhea 
  • Unexplained weight loss 
  • It’s a regular occurrence 

We asked our sleep advisor and medical reviewer, Dr. Chester Wu, for his take on the topic: 

“Feeling too hot when you sleep is not only uncomfortable, it can make it harder to fall asleep. Try using a fan or air conditioning to cool down your bedroom, taking a warm shower or bath before bed, and avoiding night sweat triggers like caffeine and alcohol. If you’re still feeling too hot at night, reach out to your healthcare provider.” Rise Science Medical Reviewer Dr. Chester Wu

Not sure how much sleep you should be aiming for? RISE can work out your individual sleep need down to the minute. 

​​RISE users on iOS 1.202 and above can click here to view their sleep need.

Cool Down to Drift Off 

Feeling too warm is never a nice feeling, but it’s especially uncomfortable at night when being too hot can get in the way of a good night’s sleep. 

The good news is, most of the time, your body can regulate its own temperature — you just need to get out of its way and let it do its thing. How do you do this? By maintaining good sleep hygiene. 

Good sleep hygiene doesn’t just involve setting your bedroom to the right temperature, it includes other healthy sleep behaviors like getting and avoiding light, caffeine, exercise, and alcohol at the right times. 

The RISE app can guide you through 20+ sleep hygiene habits and tell you the ideal time to do each one. All this can help you fall asleep faster, wake up less often throughout the night, and reduce the chances of anything hiking your body temperature when you’re trying to drift off. 

Summary FAQs

Why do I get so hot when I sleep?

You might get hot when you sleep due to a warm bedroom, thick pajamas or bedding, having caffeine or exercising too close to bedtime, stress, being pregnant or going through menopause, being ill, medication, or having an underlying medical condition.

Why do I get so hot when I sleep even when it’s cold?

You might get hot when you sleep even when it’s cold due to thick pajamas or bedding, having caffeine or exercising too close to bedtime, stress, being pregnant or going through menopause, being ill, medication, or having an underlying medical condition.

Why do I get so hot when I sleep female?

You might get hot when you sleep due to hormone fluctuations during your menstrual cycle, pregnancy, or menopause. A warm bedroom, thick pajamas or bedding, having caffeine or exercising too close to bedtime, stress, being ill, medication, or having an underlying medical condition may also cause you to feel hot when you sleep.

How do I stop being so hot when I sleep?

Stop being so hot when you sleep by cooling down your bedroom, using thinner bedding and pajamas, wearing socks to bed, taking a warm shower or bath before bed, reducing stress, and avoiding exercise, alcohol, and caffeine late in the day.

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