Why Do I Get So Hot When I Sleep?

After a long day, you're finally ready to slip into bed. You breathe a big sigh of relief and think to yourself, ‘What a long day. I’m so ready to sleep.’

Shortly after you’ve drifted off to sleep, you start to feel the toss and turns start. First, you kick off the blanket and turn to the other side. That helps for a little while. Things start to get warmer and warmer and you start to wake up more and more.

Finally, you wake up drenched in sweat, sticky and uncomfortable.

Frustrated and annoyed with another rough night of sleeping, you have to ask - “why do I get so hot when I sleep?” It’s almost as if you just ran a marathon. It’s actually a common question, and we’ve definitely been there too.

As you continue to read, we’ll share some science behind why your body gets hot at night and how to sleep cooler, longer, and deeper.

Why Do I Radiate So Much Heat at Night?

We’ll explore the science of sleeping hot. Your core body temperature drops during sleep and rises to help us prepare to wake up. But, when our body temperature drops, it releases heat into the surrounding area, including the mattress. In fact, one person can release up to 100 watts of excess heat.

Human Body Temperature: The average standard human body temperature is 98.6ºF, and some studies consider the average temperature between 97ºF - 99ºF.

Add a second person or even children and the number grows. When this occurs, some people are more sensitive to this phenomenon than others, making them wake up hot in the middle of the night.

If you’re sleeping in those flannel pajamas and with that wool blanket, those might be sealing the heat around you and can contribute to overheating at night.

Sleep Study: Research recently showed that “hot sleepers” can affect 10% to 41% of people. [1, 2]

Why Do I Get Hot When I Sleep?

Healthcare professionals generally refer to true night sweats as repeated episodes of severe hot flashes and heavy sweating during sleep that soak through your pajamas and sheets. Sweating is often caused by illness or underlying conditions.

Some possible conditions that would warrant a call to your doctor.

Even if your bedroom is set at the recommended temperature for sleep, usually between 66 to 70ºF, it can still feel too warm throughout the night. This can be caused by several factors, including your pre-sleep routine, your bedding and bed, certain medical conditions, and some medication. [3] They can all play a role in making you feel in your bed and resulting in sleeping hot at night.

Let’s explore other reasons that can help answer the question - Why Do I Sweat in My Sleep?

Menopause

Women in perimenopause or menopause [4] often experience hormone-related hot flashes and night sweats.

We were recently involved in a Wake Forest menopause study, which studied the role of sleeping colder and symptoms, including hot flashes and sweating at night.

Menopause Statistics: Approximately 80% of women experience hormone-related sweats and hot flashes. [5]

Sleepme Menopause Study Result

Women in the menopause study said sleepme’s cooling products significantly changed their sleep patterns and sleep ability. [6] Below are the findings:

• 57% saw a decrease in the severity of hot flashes
• 60% saw a decline in the frequency of hot flashes
• 64% saw a decrease in the frequency of night sweats

Hormonal Changes

Hormonal changes during pregnancy can cause increased blood flow and a rise in body temperature. Obstructive sleep apnea and hyperthyroidism are two distinct causes of why you might be hot at night.

Low testosterone levels in men have been identified as a probable cause of night sweats in men and sleeping hot. Temperature-controlled sleep is vital for repairing muscle after a hard day’s work, improving cognitive function for starting the day feeling alert, and restoring testosterone levels.

Did You Know: Men often have night sweats, but they experience fewer than women, possibly because menopause is a leading cause of sleeping hot and sweating at night.

Medication Side Effects

Certain medications can also make people sleep hotter at night, potentially raising your body temperature and inducing excessive sweating:

• Migraine medications in the triptan family (zolmitriptan, rizatriptan, etc.) cause excessive sweating as a side effect.
• Cortisone, prednisone, and prednisolone may be associated with flushing or night sweats. [7]
• Some antidepressants.
• Certain diabetes medications may increase sweating, primarily if used alongside alcohol.
• Over-the-counter medicines taken to lower fever (aspirin or acetaminophen) can sometimes lead to sweating and affect the body’s ability to regulate temperature.

Contact your doctor and see if you can adjust certain medications.

Stress and Anxiety

Anxiety can increase the chance of people getting hot and beginning to sweat because the body's stress response has been activated (with the changes in heart rate, body temperature, etc.). [8] It's normal to have a physiological response to the fear of your dream, especially if you've experienced nightmares.

Did You Know: An overactive mind can accelerate your body, resulting in sweating and feeling hot in bed.

Infection

Many Infections, such as tuberculosis and several bacterial infections, including abscesses, osteomyelitis, and endocarditis, can lead to intense sweating at night. This occurs because infections can trigger overheating and fever.

Pre-sleep Activities

Before bedtime, without knowing it, some activities you perform can potentially increase your body temperature and make it more difficult to fall asleep.

• Caffeine: Consuming close to bedtime can make it difficult for some to fall asleep as it can increase our core body temperature.
• Exercise: Sleep may be impaired if an individual performs intense exercise leading up to bedtime.
• Sex: Like exercise, sex can increase your heart rate and body temperature.
• Stressful Activities: Your blood vessels constrict when feeling stressed, causing your skin temperature to drop and increase your core temperature.
• Spicy Food: Consuming before bedtime can affect the severity of sweating.

Bedroom and Sleep Environment

Are you aware that your sleep environment starts to heat up as you lay there? This can include an increase in room temperature and humidity.

As mentioned above, our core body temperature plays a significant role. We need to drop our core temperature by about three degrees Fahrenheit to initiate sleep and then stay asleep. In scientific terms, your circadian rhythm is how your body understands when it's time to go to sleep.

Your body's sleep-wake cycle is affected by melatonin secretion and your core body temperature changes. Sleeping too hot -- and frequently waking up due to sweaty sleep -- can throw your body's natural cycle out of alignment and disrupt sleep quality.

Keep in Mind: Sleeping at a cooler temperature is critical to improving deep sleep!

Other factors can include sunlight. During the day, the sunlight that your home is exposed to heats the floors, walls, and other spaces. The heat is absorbed and retained. The sun goes down, and there’s no more heat to absorb. The walls and floors begin to release the heat from the day back into the room.

Hot Sleeper Fact: 4 out of 5 people report that cool temperature is one of the most important factors of getting a good night’s sleep. [13]

But it isn’t just the heat radiating back into the room that can disrupt the temperatures in your bed. Why is it that we can fall asleep so comfortably, warm and cozy, and wake up hot and sweaty an hour later?

Most Likely Answer: While it may be that your bedroom and bed are too warm, there are other causes too. Add a few of them from above and put them together and you’ve got a consistent sleep struggle.

Idiopathic hyperhidrosis

It’s a condition where the body chronically produces too much sweat, usually presenting without any identifiable medical cause.

Why is My Body Cooling Down at Night?

Picture it. You are a marvelous prehistoric man or woman just chilling in your cave. As the sun goes down, your body temperature drops, and suddenly your brain says,

“Hey, sleep sounds like a good idea.”

Source: NIH.gov

This sleep pattern is how we have been wired since the beginning of time. Our bodies getting colder at night may not sound like something that makes sense at first thought but it’s day/night light patterns that are the instigator here.

As light enters through our eyes and crosses through to the hypothalamus. The hypothalamus then works through the production and secretion of melatonin. Studies have found that melatonin prompts a cycle in the body that lowers the temperature in preparation for sleep.

Melatonin levels naturally tell our brain to slow down, stop all activities and fall asleep. Similarly, higher body temperatures prompt our brain to be more alert and coincide with daytime light hours.

Long Story Short: When nighttime comes, your body releases heat to bring your body temperature down to prepare you for a night of fantastic sleep.

How to Stay Cool While Sleeping?

If you're one of the 10% to 41% of people who sleeps hot at night, there are different options to cool down while sleeping.

Temperature-Regulated Sheets

Especially during the summer months, having cold sheets will be necessary to help you stay cool at night. Owning a set of cooling sheets can help as they are designed to move moisture quickly away from the body, creating a cooler, more comfortable sleeping environment.

Avoid Alcohol Before Bedtime

Alcohol tends to disrupt your sleeping patterns and ability to go to sleep, but it can also influence how much you sweat. Even if you’re not prone to sleeping hot when drinking alcohol, your blood vessels dilate and your heart rate increases, provoking perspiration while sleeping.

Learn more about how alcohol affects sleep.

Take a Deep Breath

The overabundance of anxiety and stress can cause people to sweat. Did you know that over 45% of Americans say they are concerned about the amount of anxiety in their lives?

Sleep Study: Skin Temperature Reveals the Intensity of Acute Stress [9]

Practicing various relaxation methods such as meditation, yoga, yoga Nidra, or deep breathing exercises can help you control anxiety and stress. Give them a try before bed or even read for a few minutes before you fall asleep; it could help you unwind, decrease the chance of sleeping hot, and improve overall sleep quality.

• 30-Minute Gradual Peace by the Campfire
• 15-Minute Ocean Sleepscape
• 10-Minute Yoga Nidra Sleep Meditation

Did You Know: An increase in body temperature can affect a person's sleep cycle and behaviors and affect moods and attention spans. Plus, it severely influences both mental and physical well-being.

Hydration and Sleep

Whether you know it or not, your body loses a lot of water, nutrients, and minerals when you sweat. Leading up to bedtime, place a glass of cold water by your bed at night. Take a few sips if you wake up in the middle of the night sweating, as it can help you cool down. If you feel yourself beginning to heat up, proactively sip on the cool beverage.

Keep in Mind: Drinking water at night has its benefits, but it can be disruptive to your sleep, potentially leading to frequent nighttime wakings to use the bathroom.

Sleepwear

If you suffer from your body overheating at night, you’re probably no stranger to having to change your sheets, or even your pajamas, in the middle of the night. It would be best to try to wear loose-fitting and comfortable clothing, [8] paying close attention to the fabric.

Avoid flannels and polyesters as they tend to trap your core body temperature and increase the chances of sweating. Instead, select more natural and softer fabrics such as cotton.

Pajamas and other sleepwear made from bamboo naturally cool the skin temperature and are 100% biodegradable. Or if natural is your thing, don’t wear anything at all. We promise we won’t judge. It would help if you also kept these fabric tips in mind when purchasing your bedding.

Did You Know: Common Sleeping Preferences

• 52% sleep partially clothed
• 31% sleep fully clothed
• 17% sleep naked.

Adjust the Thermostat

Whether hot or cold, consider your room temperature for a quick and easy fix. You can easily adjust your thermostat to your preference, and the temperature change could quickly get expensive, mainly depending on the hot weather and the time of year.

Ceiling fans are also an easy fix, although depending on the strength and location, a fan might not be able to cool you down completely. Ceiling Fans are known to circulate air, not necessarily cool your body temperature.

Hot Bath Before Bedtime

Yes, you read that correctly. Take a hot bath an hour or so before bed. Sure, this will increase your body temperature initially. When your body cools down, it helps your body get ready for bed.

Sleeping Tip: Not only can it help you cool down, a warm shower or bath a few hours before bedtime can help you unwind and fall asleep faster. [10]

Avoid Strenuous Exercise Before Bedtime

Finding time to exercise with a busy schedule can be challenging, making the evening hours an option. If after work is the best time for your exercise routine, try not to do anything too vigorous before bedtime, as this can elevate your body temperature.

Recent studies have proven that an exercise regimen can help promote sleep. [11] However, an intense workout 60 minutes before bedtime can ultimately increase the time it takes you to fall into a deep sleep. It can reduce the total amount of sleep overall and make you more likely to wake up during the night.

Invest in a Cooling Mattress Toppers

At sleepme, we offer various sleep systems and cooling products that can help cool you down and allow you to fall asleep faster, stay asleep, and wake up rested.

Whether your bedroom's ambient temperature or your body's heat load, our cooling bed systems, and mattress pads are designed to keep your bed at the precise temperature, you want all night long, ranging from 55º to 115º degrees Fahrenheit.

Our cold mattress pad works as a barrier between your body and the mattress, preventing the mattress from absorbing your body heat to improve sleep quality and help you sleep more comfortably and, most importantly…cooler at night.

Chris Winter, the president of Charlottesville Neurology and Sleep Medicine in Virginia and author of two books on how to get better sleep, recommends sleep systems for individuals experiencing night sweats and sleeping hot:

“If you like a cold bed, this thing is amazing,” he said. He recommends sleepme to many professional athletes who sleep hot, and his medical colleague has found it helpful for menopausal patients.

When to Be Concerned About Sleeping Hot?

Having night sweats and sleeping hot periodically are usually nothing to be concerned about.

Suppose you find that adjusting your pre-bed habits, adjusting the air conditioning, and the temperature in your bedroom hasn't resolved the issue.

In that case, set up an appointment with your primary doctor to rule out an underlying medical condition or symptoms that may include chills, fever, unexplained weight loss, or pain.

If it often occurs, write down how often you get hot in your bed and the symptoms you experience in a notebook. Keeping a journal can help you; your doctor may discover why you sweat and the potential cause of sleeping hot at night.

Takeaway

As you can see, there are many factors on why you sweat in your sleep at night. Some items include bedroom temperature, pajamas, illnesses, and certain medications that can all contribute to your feeling too hot at night.

Given that we spend approximately one-third of our lives in bed, [12] it's important to find a solution to eliminating sleeping hot and getting a good night's sleep. Whether it's a cooling mattress pad or merely adjusting your workout regimen, slowly make adjustments to see what can help you.

Remember, it might be best to set up an appointment with your doctor to rule out an underlying medical condition.