Benefits And Side Effects Of Sleeping With A Fan On All Night

I come from one of the hottest places, and I’ll admit that it’s hard to decline the pleasure of the chilly breeze generated by the spinning blades.

For that reason, I’d completely understand if someone declared they can’t sleep without a fan, especially during the hot summers.

does sleeping with a fan on dehydrate you

However, have you ever wondered if sleeping with a fan on all night would affect your health in any way? I have.

And, when I decided to do some research on this subject, I found some publications that kind of made me think twice about my habit.

While they were not really convincing or genuine reasons why I should stop running my fan every night, the ideas I came across are something I needed to look into if I wanted to enjoy or keep using my fan, especially at night.

So, I’ll share them with you, but you have to keep two things in mind; it always depends on the person using the fan and the condition of your house. If you have any underlying health issues, it’s important to weigh your options carefully before choosing to sleep with a fan every night. If your indoor air is contaminated, it’s also a good idea to solve the problem first.

Before I can reveal the side effects of sleeping with a fan, let’s discuss who should and shouldn’t sleep with a fan on.

Who Should Sleep with a fan on all night

It’s totally fine to sleep with a fan on if:

  • You’re a hot sleeper. If you wake in the middle of the night drenched in sweat while other family members seems to be doing just fine, then a fan might be a good option for cooling down.
  • You’re sensitive or easily disturbed by minor noises. If you can’t sleep because of the noise from the moving cars outside, yelling neighbors, car alarms, dripping water from the tap, or any other reason, you can benefit from the white noise from the fan.
  • You’re claustrophobic – if you always worry about suffocating or experience irrational fears when you’re sleeping alone in your bedroom, the noise from a fan can help prevent that.
  • You’re fond of sleeping with a fan and you just cant help it.

Who shouldn’t sleep with a fan on all night

If you suffer from these allergy issues, then it’s best not to sleep with a fan blowing on you

  • You’re asthmatic
  • You have dry eyes or ocular allergies – if you suffer from itching, redness or tearing of the eyes.
  • You have skin allergies including dry, irritated skin, acne breakouts, folliculitis, heat rash, etc.
  • You’re sensitive/allergic to these pollutants – dust, pet dander, mold, pollen.

Benefits of Sleeping with a Fan on

I want to imagine you don’t suffer from any of the above allergies and all you want to know is if sleeping with a fan on could make you sick. Let me highlight some of the benefits so you can decide if they outweigh the side effects, which we’ll discuss later in the article.

White Noise

There is evidence that the soothing sound produced by fans can help some people fall asleep. Now, there are two categories of people who might benefit from white noise.

First is someone who is sensitive to noise or easily disturbed by minor noises. This person finds sleeping tough or wakes up immediately to even the slightest of noises.

The second person is someone who is accustomed to the lulling hum of the fan. These type of people either grew up and was fond to the fans blowing on them every night or used to turn on a white noise machine to help them sleep. So, it means, they can’t sleep in a totally silent room – they need some kind of ambient noise to fall asleep.

Whichever the scenario, the white noise from a fan can be an ideal sound that can help you fall asleep

Temperature Control

This is a no-brainer and it’s the absolute reason why many people use fans.

Not only can you use fans to regulate the temperature of your bedroom, but also the temperature of your body.

For you to have a normal and comfortable sleep, your body temperature must decrease. However during summer, it’s a toll order for the body to reach the temperature that aids sleep, and as a result, you find it hard to sleep. In this case, a fan would be a great solution

Also, hot sleepers who wake up in the middle of the night to find themselves covered in sweat would find a fan a good buddy.

Air Circulation

You might not like a fan blowing on you as you sleep, but I imagine you hate stale air more.

Fans can help circulate air across a room thus providing a constant fresh air.

If you’re claustrophobic – you always worry about suffocating or experience irrational fears when you’re sleeping alone in your bedroom, the noise from a fan can help prevent that.

However, if you have allergy issues, make sure your room is free of allergy-triggering contaminants. If not, the fan can circulate the pollutants across the room which might trigger allergy and other health issues.

Make sure you clean your house for dust, mold, pet hair, roaches, pollen, and chemicals.

Sudden Infant Death Prevention

Kaiser Permanente, a healthcare management group conducted a study in 2008 to determine the relationship between running a fan all night in a baby’s room and sudden infant death syndrome (SIDS) risk.

The study concluded keeping a fan on when babies sleep could dramatically lower the risk of SIDS risk by 70 percent.

That means young infants whose mothers use this common and modest electronic have higher chances of surviving SIDS than babies who sleep in poorly ventilated rooms.

Moreover, opening windows at night was found to lower the risk of SIDS and suffocation, although the association was not significant.

The real reason why such an environment is suitable for infants is that the concentration of carbon monoxide across the room is decreased. So, the harmful, poisonous gas exhaled by the baby is expended before she can reinhale.

Side Effects of Sleeping with a Fan on all Night

As I mentioned before, sleeping with a fan on can have effects on your health, particularly if you’re sensitive to air pollutants, so you need to make sure you’re safe.

Here are some of the consequences you’re likely to face


Dehydration is one of the common problems in rooms where fans are left running all night.

Fans are intended to circulate the air inside the room. By doing so, they help us feel and sleep soundly because our bodies are exposed to cool air from the outside environment.

However, if you use an electric fan, you might be doing more damage to your body than good. The ideal temperature for electric fans to get their job done is below 95 degrees Fahrenheit.

The problem arises when the temperature rises above 95 degrees F or roughly the body temperature. This causes the fan to blow hot air across your skin, which make you even hotter, unable to sweat and sick.

When this continues for a while, the rate of dehydration or heat exhaustion increases.

Headaches and Migraines

Another unfortunate side effect of leaving your fan on all night, especially when it reaches a point where it blows dry air, is your susceptibility to headaches and migraines.

According to some studies, cold temperatures stimulate the trigeminal nerve, causing your brain’s blood vessels to constrict and thus create a headache.

Other studies also claim that fans do not directly cause headaches or migraines directly, but if the air inside the room is still, you might develop some allergies which might manifest in the form of headaches or migraines.

Drying of the Throat/ Mouth​

Come summer, excessive use of fans combined with dry indoor air can lead to dry throat and mouth.

Because some people sleep with their mouths open, they breathe the dry air through their mouths and noses which in turn causes dryness in the mentioned regions. This can disturb your sleep as you may be forced to wake up in the middle of the night to drink some water.

Although these effects may clear away within a few minutes if you re-hydrate, continuous drying of throat and mouth can cause gum and teeth diseases.

Sinus Problems

Fans might not necessarily be the cause of sinus infections. However, in some cases, they trigger certain reactions that may negatively affect your sinus.

One common problem is dry air which causes drying in the nasal passages. As a result, the mucous membrane becomes irritated, dry, and unable to perform its function.

In the absence of adequate protective mucus, it becomes difficult for the cilia to trap unwanted particles such as dust, irritants, bacteria, allergens, and viruses, making you vulnerable to sinusitis-causing microorganisms.

If you find that your sinus problems come out or become worse when you use a ceiling fan in your room, it is best to avoid it at all costs. You can opt for the air conditioning or humidifiers which can serve the same purpose as the fan more healthily and safely.

Asthma and Allergies

Leaving a fan running as you sleep could make asthma and allergies worse.

While an air-cooled space can be a healthy environment for sleeping, especially for some people who are sensitive to pollen or indoor air contaminants, asthmatics individuals or those prone to getting allergies may suffer.

If you fan isn’t properly maintained or cleaned regularly, it might collect dust mold spores, allergens, and other indoor pollutants and distribute them across the room, which in turn enter your sinuses and lungs.

As an allergy or asthma sufferer, this is something you don’t want to experience because you’ll not only lose your sleep but also have a difficult time controlling your condition.

Respiratory Problems

The symptoms of upper tract respiratory infection tend to appear much more in people who leave their fans on overnight than those who don’t.

These symptoms may include nasal congestion, sore or scratchy throat, shortness of breath, sinus pain, rhinitis, or even cough.

According to some studies, people that spend a lot of time in rooms constantly cooled using fans are prone to rhinitis than those that use natural ventilation. Moreover, symptoms of nasal congestion, nasal discharge, and nasal breathing were found to be common in people that use mechanical ventilation.

If these problems are not looked into, they can cause severe respiratory problems in the long run.

Become Bad Habit/Addiction

Don’t think it’s only smoking that is addictive. If you can’t sleep without a fan, then you might be addicted to that habit without noticing.

The bad thing, if you can’t sleep without using blowing fans, then it will be difficult to stop even when it’s harming your health.

The result is you won’t be able to sleep in rooms without fans, and you’ll likely suffer from most of the issues we’ve discussed in this post. It’s only wise to use your fan when it’s really necessary.

Read also: Bathroom Fans with light and heater combination


As you might know by now, there are no rules to sleeping with a fan on all night. It all depends on the environment you’re in, your condition, and how much risk you’re willing to take.

If you’ve been sleeping with a fan on from your childhood all through to your adulthood, then there is no issue. However, if you have allergy problems, it’s only safe that you cool your room a few hours before sleeping so that you switch your fan off.

Whatever you decide the best option is, make sure you clean your fans regularly and keep your indoor air fresh and healthy.


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Photo of author
Ronald Watford, the owner of Quality Home Air Care, is a qualified HVACR technician and manages the team of expert writers on this site. He believes that educating homeowners about HVAC systems is one of the most impactful aspects of his job.