Even if you don’t sleep hot or cold, you’re probably aware your body temperature changes throughout the night. Body temperature is important for overall sleep quality. It’s crucial to understand how thermoregulation works, so you can achieve a better night’s sleep. A fever can also be a game changer – so we’re going to wrestle with this topic so you know what to do.
What changes body temperature at night?
Human beings are able to regulate our body temperature. Body temperature is maintained through a balance of heat absorption, production and loss. Human temperature must be maintained within a fairly small range, up or down from the resting temperature of 36,5 C. Temperatures above 42 C and below 33,5 C generally cause injury or death.
Humans have two zones to maintain. First is their core temperature and other is their shell temperature. Core temperature is temperature of stomach, chest and skull cavities that contain important organs. Shell temperature is the temperature of our skin, tissues and muscles. While core temperature is controlled by our brain, shell temperature is more affected by external condition. The core temperature can be conserved or released through the shell.
How does the temperature change throughout the day?
When we wake up, our body temperature is at its default value. During the morning and through the late afternoon our temperature raises giving us the energy and helping us stay alert and awake. That’s why working out is so effective, the body heat raise makes us feel awake.
After that rise in energy comes the down time, so called afternoon slump. Our body starts to lower the temperature in order to prepare us for the sleep. At 5am, several hours before you’d wake up, your body temperature is at its lowest.
A cooler core body temperature is associated with sleep. Conversely, a warmer core temperature is energizing. Think about how awake you feel during exercising, and it starts to make sense. Human performance scientists have found a higher internal body temperature correlates with more alertness, better memory, and improved reaction times.
Body temperature and sleep quality
There was a recent study that shows correlation between body temperature and sleep quality. The researchers put human participants with thermosuits. Raising their skin temperature less than a degree resulted in significant changes in sleep quality. People didn’t wake up as much during the night and the percentage of the sleep spent in deep sleep increased. The effects were most pronounced in the elderly and in people who suffered from insomnia.
Can you manipulate your core body temperature during sleep?
The answer is no, at least not unless you’re severely ill. It is very dangerous if you temperature goes more than a few degrees above or below normal.
However, many find that cooling down before bed helps them get to sleep.
During REM sleep, your brain stops working to regulate your body temperature. Even the hypothalamus needs a break. This is why it’s so important that the external factors in your sleep environment (your room temperature, clothing, and bedding) are conducive to keep you cool.
Ideal temperature for sleep
The ideal temperature in a bedroom for falling asleep is between 17 C and 19 C degrees. Find the temperature that works best for you. It should be cool enough to help you fall asleep without waking up a few hours later shivering, but also without being too warm to cause you to wake up from sweating.
What else could you do to keep yourself cooler?
First of all, use less bedding. With both your bedding and pajamas, opt for more breathable fibers like cotton or linen over heat-trapping synthetics like polyester.
As mentioned above, a warm bath helps cool down your body temperature, as the moisture quickly evaporates from your skin upon stepping out of the tub. Try taking a bath 1 hour before bed for optimal effect.
Cold and flu
If you’ve got a cold, or maybe even the flu, you’d feel like not doing anything except sleeping. Or at least until you try to sleep with a flu. Then you realize your condition makes any kind of sleep nearly impossible. Cold and flu symptoms seem to get worse at night at the crucial time, when your body needs rest the most. In addition to the pure discomfort of the symptoms themselves, increased mucus production, along with overall congestion, forces us to breathe through our mouth instead of our nose. When we lie down, congestion can seem worse. Mouth breathing also irritates airways, causing us to cough more often, which in turn can also disrupt sleep.
Also, when we are ill our organism releases certain immune factors into the bloodstream, some of which are mediators of sleep. The end result is that you toss and turn all night. And even if you manage to fall asleep, you wake up feeling drained and tired, with cold and flu symptoms seemingly worse.
Choose medicine wisely
Many people use cold medicine at night, but that’s not always helping them to sleep better. Actually, sometimes the medicine they chose might make things even worse.
Everybody reacts to the medicines differently. Some people would fall asleep easier, but others might become jittery and nervous, which prevents them from falling asleep and staying asleep. There are some ingredients in cold pills and cough medicines that make people feel unsettling. Other ingredients have controversial effect, making some people sleepy and others not.
Fever and night sweat
Fever is a state of heightened body temperature, usually followed with sweating, shivering and feeling of exhaustion. It is a common sign that on its own is usually little help in making a diagnosis. Persistent high fever needs urgent treatment. Fever over 42.2° C produces unconsciousness and leads to permanent brain damage if sustained.
Most cases of fever are due to self-limiting viral infections, especially upper respiratory tract infections and childhood exanthemas.
Urinary tract infections are also common but more severe infections should always be considered. Recent foreign travel should prompt consideration of referral to secondary care for full investigations for tropical infections like malaria.
Night sweats are usually defined as episodes of significant night-time sweating that soak the bedclothes or bedding. This is a fairly common symptom. Although uncomfortable, night-time sweating typically isn’t a sign of a serious underlying medical condition. It may be triggered by something as simple as too warm a room or too many blankets on the bed.
What to do during fever?
First and foremost, drink lots of fluid. Do not wear too many clothes (but don’t underdress either) or use too many blankets. Keep the room at a comfortable temperature but make sure that fresh air is circulating (use a fan if available). A damp vest and a fan can be effective in lowering temperature. Very important, don’t wipe the sweat off immediately as this helps to cool the body. Cool baths and tepid sponging are not recommended.
Body temperature is important for overall sleep quality. Human body have two major thermoregulation zones, core and shell. Core temperature is automatically regulated by brain, except during REM phase of sleeping. Body temperature tends to fluctuate during the day, getting lower as the sleeping time approaches. There’s also a strong correlation between body temperature and overall sleep quality, as the minor change in core temperature significantly changes sleeping duration and depth.
Of course, there are symptoms of illness during which body temperature raises way over average, which are usually manifested by fever, night sweat and clogged airways. These symptoms affect sleeping quality in great measure, even nullifying all the good effects of sleeping. In order to snatch few hours of precious sleep, you need to modify the room so it regulates the temperature and air flow better.