Why Do I Get So Hot When I Sleep? The Top Causes

Waking up feeling too hot at night is a common issue that can be caused by various factors, such as wearing warm clothes or bedding, experiencing hot flashes, taking certain medications, or having an underlying medical condition.

The human body maintains a consistent temperature during the day, which naturally drops by approximately 1.8 degrees Fahrenheit at night to promote better sleep.

However, some still feel uncomfortably hot while sleeping due to their sleep environment, dietary choices, unique body composition, or other medical reasons.

A recent sleep study showed that "hot sleepers" can affect between 10% to 41% of people. [1, 2] Below are some of the most common reasons you might be getting hot at night and how to address them to sleep better at night.

Possible Reasons Why You’re Sleeping Hot

Imagine your bedroom being too hot or too cold. Yuck! It's no surprise that these extremes can make it challenging to fall asleep. In fact, research shows the ideal room temperature for sleep is around 66 to 70 degrees Fahrenheit (19 to 21 degrees Celsius) [3]. So next time you're having trouble falling asleep, check your thermostat! Maintaining an optimal temperature in your bedroom can help improve your sleep quality.

Even if your room temperature is perfect, you might still wake up feeling hot. Why? There are a few sneaky culprits that can make you overheat at night. These include things you do before bed, your pajamas and bedding, and even some health issues and medications [3].

Here's the thing: while the average human body temperature is around 98.6ºF (with some studies considering a normal range between 97ºF and 99ºF), our bodies can actually release a lot of heat – up to 100 watts! That's like having a light bulb burning under the covers!

That's why creating a cool and comfortable sleep environment can help your body regulate its temperature throughout the night.

Sleep Environment and Bedroom

A person's sleep environment can contribute to them feeling excessively hot during the night.

Hot or Humid Climate

As we mentioned above, the best temperature for optimal sleep is between 65 and 68 degrees Fahrenheit. High temperatures and the presence of warm, humid environments can interfere with the body's ability to cool down.

Heavy Bedding

Certain types of sheets and blankets are made to keep you warm by trapping heat. It's best to avoid fabrics like fleece and down that hold body heat, especially during the summer.

Note: Using breathable bedding can help keep your body temperature cooler during the night.

Warm Pillows and Mattresses

Do you ever wake up hot at night, even when your room feels cool? The culprit might be your mattress! Some cozy materials, such as memory foam, can retain and trap heat, causing you to feel warm all night long. This is particularly the case for individuals who have a tendency to sleep hot. But there's good news! Bed cooling systems can help! Chilipad Dock Pro and Chilipad Cube work with your existing mattress to keep it cool and comfortable all night long.

Thick Sleepwear

Your comfy PJs might be the culprit! Thick fleece or wool pajamas, while undeniably stylish for lounging, can trap heat and make you feel uncomfortably warm all night. This is especially true for people who tend to sleep hot. Opt for lightweight, breathable fabrics like cotton or linen.

Sleeping Partners and Pets

The average adult generates between 75 and 90 watts of heat while sleeping, so sharing a bed with a partner, child, or pet could raise the bed temperature to uncomfortable levels. Can't agree on the thermostat? We've included the best sleep temperature tips for couples.

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

Foods and Drinks

What you eat and drink before bed can surprisingly affect your body temperature at night. Although there isn't much research on this topic, some studies suggest that certain foods and drinks might raise your body temperature, including;

• Spicy food
• Heavy and protein-rich meals
• Caffeine
• Sugary energy drinks

Related Blog: What Foods Keep You Awake at Night?

The good news? Sticking with lighter meals, opting for water, and avoiding spicy dishes can help your body regulate elevated body temperature more effectively. This translates to a cooler, more comfortable sleep environment, perfect for drifting off to dreamland.

Hormonal Changes

For women, hormonal fluctuations can disturb sleep and affect body temperature. Here's how:

Estrogen

Estrogen decline during perimenopause and menopause can disrupt body temperature regulation, causing hot flashes and night sweats.

Progesterone

Another key hormone, progesterone, also helps regulate body temperature. Its levels decrease during perimenopause and menopause, contributing to feelings of warmth and difficulty staying cool at night.

Thyroid Hormones

The thyroid gland produces hormones that control your body's metabolism, which affects heat production. An underactive thyroid can make you feel cold, while an overactive thyroid can make you feel hot at night and cause sleep disturbances.

Night sweats and hot flashes rank among the most prevalent symptoms of menopause. The decrease in estrogen and other hormonal shifts, which are not entirely understood, are believed to be the root cause of these symptoms.

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

Pregnancy also triggers hormonal changes that result in increased blood circulation and a rise in core body temperature.

Hormonal changes aren't solely a woman's issue. Men can also experience sleep disruptions due to hormonal fluctuations. Low testosterone levels in men have been linked to night sweats in men and difficulty regulating sleep temperature.

Related Blog: Understanding Hot Flashes at Night

Stress and Anxiety

When stress and anxiety sneak in before bed, they can become unwanted companions that disturb your sleep and leave you feeling restless.

Stress can have a direct impact on your body, including your skin temperature. When you're stressed, your blood vessels tighten, causing your skin temperature to drop. At the same time, your core body temperature rises, which may explain why you feel so hot during the night.

Here's why:

• Fight-or-flight Response: When stressed or anxious, your body goes into fight-or-flight mode, releasing hormones that prepare you for potential danger. This can lead to increased heart rate, blood pressure, and body temperature, making it difficult to relax and fall asleep. [6]
• Muscle Tension: These tense muscles can produce heat, adding to the feeling of warmth and discomfort when trying to sleep.
• Sleep Cycle Disruption: The stress hormones released during fight-or-flight mode can disrupt your natural sleep cycle and make it harder for your body to regulate its temperature effectively, leading to fluctuations and feelings of being hot.

Try practicing deep breathing exercises, as they can help in managing feelings of anxiety and stress leading up to bedtime.

Did You Know: When you’re feeling anxious or stressed, your body releases cortisol, which increases your heart rate and boosts blood flow, leading to a rise in body temperature.

Body Composition

Have you ever wondered why some people seem to sleep cooler than you? It might be partly due to their body type. People with more muscle tend to burn more calories, even while sleeping, making them feel warmer.

They might also have a higher basal metabolic rate, a higher core body temperature which generates more heat. On the other hand, fat tissue acts like insulation, trapping body heat—not ideal for those who already tend to sleep hot.

While many things affect your sleep temperature, having more muscle and a healthy body weight can make a difference. These factors help your body regulate temperature better, leading to cooler nights.

Studies suggest that people who weigh more may be more susceptible to heat and may prefer lower temperatures. [7]

Pre-sleep Activities

Be aware that certain activities before bedtime, often done unknowingly, can raise your body temperature and hinder your ability to fall asleep. Understanding these activities can help you make better decisions and enhance your sleep quality.

• Caffeine: Consuming close to bedtime can make it difficult for some, as it can increase core body temperature.
• Exercise: Performing intense exercise right before bedtime can interfere with your sleep. This can lead to elevated heart rate, adrenaline levels, and increase core body temperature, making it harder to fall asleep.
• Intimate Activities: This can improve sleep quality by triggering the release of hormones that encourage relaxation. Vigorous activity that elevates your heart rate can have a similar impact as exercising.
• Stressful Activities: When you're stressed, your blood vessels narrow, which can cause your skin temperature to drop and your core body temperature to rise.
• Spicy Food: Having something to eat or drink before going to bed can play a role in how hot you feel during the night.
• Alcohol: It can raise your core body temperature by affecting your blood vessels and disrupting your body's ability to cool itself.

Medication Side Effects

Certain medications can also cause people to feel warmer while sleeping, leading to increased body temperature and excessive sweating.

• Migraine medications in the triptan family can cause excessive sweating as a side effect.
• Cortisone, prednisone, and prednisolone may be associated with flushing or night sweats. [8]
• Some antidepressants.
• Certain diabetes medications may increase sweating, primarily if used alongside alcohol, which can be a reason why you get so hot.
• Over-the-counter medicines taken to lower fever (aspirin or acetaminophen) can sometimes cause sweating and affect the body's ability to regulate temperature.

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

Nightime Fever

Feeling hot during a fever might seem counterintuitive, but it's actually your body's way of fighting off infection. When you're sick, your immune system cranks up the heat, raising your internal temperature set point in the brain. This initial warming might involve shivering or achiness.

Once your body reaches this new, higher temperature, it goes into overdrive, trying to cool you down. Sweating is a key part of this process, as it helps release heat and bring your core temperature closer to normal.

The confusing part is that even though your body is working hard to cool you off, the elevated set point itself makes you feel hot. So, while you might be sweating in a chilly room, the body's adjusted temperature target, not a lack of cooling, is causing the feeling of feverish.

Tips to Sleep Cooler at Night

Feeling hot and tossing off the covers all night? You're definitely not alone. Many of us struggle to stay cool while sleeping. But don't worry! We've got effective ways to beat the nighttime heat and get a cooler, more peaceful sleep.

Check out our blog for useful tips on how to stay cool while sleeping! Remember, cooler temperature = more slow wave sleep/deep sleep.

When Should I Be Worried About Sleeping Hot?

Feeling hot or sweaty sometimes during sleep isn't necessarily a cause for concern. Try adjusting your bedtime routine, changing the air conditioning temperature, or making your bedroom cooler. These changes might do the trick!

However, if you frequently wake up sweaty or feel hot throughout the night, it's best to schedule an appointment with your primary doctor. They can help identify any underlying medical conditions that might be causing these symptoms, like chills, fever, weight loss you can't explain, or pain.

Keep a sleep journal for a few nights. Record how often you feel hot in bed and any other symptoms you experience. This information will be like a roadmap for your doctor, helping them pinpoint the cause and recommend the best course of action.

Final Thought

We've explored several reasons why you might break a sweat at night—bedroom temperature, PJs, and even medications can all play a role. After all, a good third of our lives are spent in bed [9], so conquering nighttime heat is key to restful sleep.

Start by making small adjustments: try a cooling mattress pad, adjust your workout timing, or experiment with lighter pajamas. If the problem persists, a visit to your doctor can help rule out any underlying health conditions.

A cool sleep environment is a recipe for deep sleep!