Sleeping Hot: Everything You Need to Know

Sleep is crucial for our physical and mental well-being. Recent studies have shown that reducing your sleep time by just 30 minutes per night can have serious consequences. Therefore, it's important to get as much sleep as possible.

However, if you find yourself feeling uncomfortably hot while sleeping, it may be difficult to enter into rapid eye movement (REM) sleep, leaving you feeling groggy the next day. One common question is, "Why does my body temperature rise at night?" There are several reasons why your body temperature may rise, and it can disrupt your sleep, leaving you feeling tired the next day.

Why is Nighttime Body Temperature Important?

You may have heard of a chemical called melatonin that your body produces every night, which makes you feel tired and enter the “ready for sleep” state. But what you may not know is that at the same time, your body temperature begins to drop, indicating that your body needs rest.

Your body temperature fluctuates between 96.8 to 100.4 degrees Fahrenheit throughout the day, providing you with a normal circadian rhythm. Your body temperature starts to drop around 8 pm and continues to decrease until around 5 am the next day. Studies have shown that the optimal temperature range for sleeping is between 60 and 68 degrees Fahrenheit, the rate of change is also important.

Sleep typically occurs when your core body temperature drops at its fastest rate, indicating the maximum heat loss from your body. This change in temperature signals your body that it's time to sleep. If your body temperature doesn't drop, especially within an acceptable range, which is much cooler than the temperature most people are used to in their rooms, it can be difficult to fall asleep and enter into deep REM sleep.

Factors that Affect Body Temperature Changes

Humans can regulate their body temperature by part of our brains called the hypothalamus, by the same token, human can maintain their body temperature. We do this by balancing heat absorption, production, and dissipation to ensure that our bodies function optimally. Even minor changes can have adverse effects and eventually become fatal.

We have two different areas to regulate body heat: core body temperature and skin surface temperature. The abdomen, chest, and head are the most important areas because they contain vital organs. This area is called the core area and has a unique temperature. The skin surface mainly refers to the skin, subcutaneous tissue, and muscles.

The skin surface also has its own temperature, but unlike the core body temperature, it's more susceptible to external temperature changes rather than being governed by the brain. The core body temperature is the most important part of our bodies, so it uses the skin surface to conserve or release heat when needed.

When the core body temperature is too high, the blood vessels in the skin expand, allowing more blood flow, with most of it being closer to the skin. Heat is lost through blood flow and skin surface dissipation. You may also notice sweating when exercising or raising your core body temperature.

When sweat evaporates from the surface of our skin, it takes away a lot of heat from our bodies, making us feel cooler. In contrast, when we're too cold, blood vessels contract and redirect blood flow away from our skin and limbs toward our organs, reducing heat loss.

Body Temperature Throughout the Day

Body temperature fluctuates throughout the day and not just at night. Typically, when you wake up for the first time, your body starts at a baseline of 98.6 degrees Fahrenheit, gradually increasing from morning until afternoon until it reaches around 100.4 degrees Fahrenheit.

Scientists have shown that the higher our body temperature, the more alert and awake we feel. You can try this out during exercise by raising your core body temperature. Although you should feel tired afterward, you'll feel happier and more alert. Around 2-3 pm, your body temperature temporarily drops, indicating that it's time for a nap.

After a nap, your body temperature rises again and peaks in the late afternoon or early evening. From there, it gradually decreases until it reaches maximum heat loss when you should be asleep. It continues to decrease throughout the night until a few hours before you wake up when it starts to rise again to wake you up and make you feel alert.

We all have a biological clock that's slightly longer than a day, but we've synchronized with the cycle of the sun rising and setting. Therefore, the hottest time of day is also when we're hottest. Once the sun starts to set, our body temperature begins to drop rapidly, producing melatonin and preparing us for sleep.

Why Does Body Temperature Rise While Sleeping?

Let's talk about this first. Your core body temperature only rises during the last few hours of sleep. Skin surface temperature may rise or fall depending on external environmental temperatures.

Nighttime Illnesses and High Body Temperature

There's an exception to this rule for women going through menopause. During this time, their bodies are in shock, and their core body temperature may be out of sync with their circadian rhythm. If you experience hot flashes during the day, you may also experience them while sleeping. If you don't have other menopause symptoms, your discomfort may be more due to sickness. The flu or other more severe conditions can cause a high body temperature because your body is trying to solve these problems. These conditions can wake you up in the middle of the night sweating and with a fever.

If neither of these factors applies, it may be too hot in your immediate environment or an inaccurate method of measuring body temperature.

High Environmental Temperature

Scientists recommend that our room temperature is between 60-68 degrees Fahrenheit throughout the night, but even at this range, you may generate additional heat, especially from clothing and bedding. If you frequently wake up in the middle of the night feeling hot or feel like your body temperature is rising throughout the night, you're likely making yourself too hot.

You may not want to give up your blankets because they're comfortable, but you need to lower your room temperature to the recommended range by scientists and reduce heat generation. You can sleep naked or use fewer blankets or thin (not dense) pillows.

Poor Temperature Measurement Methods

It's also possible that your actual body temperature hasn't risen, it's just an inaccurate measurement. If using a watch or other wearable device, it measures skin surface temperature which is related to core body temperature but reflects more external environmental overheat.

Similarly, if someone else such as your partner tells you that you're hot or if you wake up feeling hot at night doesn't necessarily mean that your core body temperature will rise.

Lowering Nighttime Temperature Leads to Better Sleep

Studies have consistently shown that body temperature is important for meaningful restorative sleep. Unfortunately, in modern society, many people choose too much comfort which increases our body temperature and disrupts our sleep.

To address this issue, especially for those who experience nighttime heat or sweating while sleeping, sacrifices need to be made. These changes can be difficult at first but will become second nature as you feel more refreshed in the morning and your body adapts to cooler nighttime temperatures.

Use Fewer or Thinner Blankets

Perhaps the most common mistake is using too many blankets, especially for those with less body fat. Unless it's cold at night, sleeping with just a thin duvet should suffice.

While covering yourself with blankets may make you feel comfortable because you can wrap yourself up in them, thick blankets prevent air circulation and trap air outside your body making it hot and preventing heat dissipation leading to overheating which makes you sweat or sleep poorly.

Use Fewer Pillows

Pillows aren't as harmful as thick blankets but many people place multiple pillows on their bed piled up together creating a huge resting space for our heads. Similarly, they hinder air circulation on the bed intercepting extra heat which usually increases bed temperatures reducing surface heat loss and preventing core body temperatures from dropping.

Those who use memory foam or sponge pillows are more harmful because they have poor breathability. Although traditional feather pillows have high foam density almost no air can pass through them which can't cool down but increase core temperatures, especially upper back and head area.

Sleep Naked

Even if you only use one duvet and one pillow while sleeping, the clothes you wear while sleeping can also affect your skin surface temperature. To address this issue, wear fewer clothes or simply sleep naked.

This will quickly lower your body temperature allowing for rapid cooling down. You may feel like there's more sweat on your duvet cover but wearing less clothing will reduce sweating overall which solves the problem fundamentally.

Lower Room Temperature

If after making all these changes you still wake up feeling hot at night or feel like your body temperature is constantly rising throughout the night then you should lower your room temperature even further than recommended by scientists, especially for overweight or muscular people.

Lowering room temperatures to 55 degrees or even 50 degrees makes a big difference. After all, if you're going to use blankets while sleeping then they should be necessary rather than purely for comfort or bodily comfort.

Take a Warm Shower Before Bed

Feeling too hot can make it difficult to fall asleep so if this is happening to you then consider taking a warm shower before bedtime. This idea may sound crazy but taking a warm shower instead of a hot shower causes blood vessels to expand so when you finish your shower your body temperature will drop far below what it was while taking a shower.

This convenient method can save lives which is why so many bloggers and health experts recommend it. Not only does it help keep distractions at bay producing melatonin and reducing stress but it also significantly lowers your body temperature allowing for quick sleep onset.

Avoid Eating Before Bedtime

There are three other factors to consider: food, exercise, and caffeine. These three factors raise your core body temperature which affects sleep especially when completed within two hours before bedtime causing core temperatures to continue rising throughout sleep onset. Instead, try eating your last meal at least three hours before bedtime drinking coffee eight hours before bedtime exercising three hours before bedtime.

Invest in a Good Mattress

It's well-known that a good mattress is essential for quality sleep especially one with the individually pocketed design which perfectly conforms to the human spine allowing for quick sleep onset.

The Novilla Hybrid Mattress with its gel memory foam effectively senses and fully conforms to human curves thereby increasing mattress fit comfort and support, gel also adds breathability preventing the "sleeping too hot" problem which is common among traditional memory foam mattresses.

Imagine how great it would feel during hot summer nights when your bed is 2-3 degrees cooler than other beds!

Conclusion

In conclusion, understanding how our bodies regulate temperatures during sleep is crucial for achieving restorative sleep every night. By making small adjustments such as using fewer blankets or thinner pillows or sleeping naked or taking warm showers before bedtime we can significantly improve our sleep quality by reducing our nighttime temperatures leading to better health overall.