Sleeping With a Fan on: Side Effects and Other Ways to Stay Cool

Many people sleep with a fan on, especially during hot summer nights. That's a good thing, right? After all, experts recommend sleeping in a dark, cool environment for restful sleep.

That said, there are some downsides to keeping the fan on all night. So if you notice new symptoms — like a stuffy nose — after sleeping with that new ceiling fan on, you may want to find other ways to stay cool. Learn more about sleeping with a fan and how this nightly routine can affect your health below. 

Is it OK to sleep with the fan on?

The short answer is that it depends.

For many people, sleeping with a fan on helps them have a better night’s sleep. The benefits of sleeping with a fan on can include: 

• Cooling the room, which can help improve sleep quality

• Creating some white noise that helps you fall asleep

• Circulating the air, which can make it feel less stuffy in the morning

• Reducing the electricity bill if you’re using a fan instead of air conditioning

But for some people, the constant flow of air can cause mild, yet uncomfortable symptoms. Those symptoms might disrupt their sleep or start when they wake up in the morning. 

What are the possible side effects of sleeping with a fan on?

Typically, sleeping with a fan on doesn't cause serious health problems. In fact, the possible risks may have less to do with fans and more with the quality of the air they circulate. Let’s take a look at a few possible side effects of sleeping with a fan on all night.

1. Worsens your allergies or asthma 

Turning the fan on before you go to bed can spread dust, dust mites, pollen, and other allergens in the room. When you inhale these swirling particles, it may trigger or worsen your allergies or asthma. And you could also wake up with itchy eyes, a runny nose, and a cough or sneeze.

2. Spreads germs, such as viruses

Fans can raise the risk of spreading germs, such as the virus that causes coronavirus disease (COVID-19). But this is typically only a problem if you don’t allow fresh outdoor air in. If you do allow outdoor air to circulate through your house, fans can actually improve ventilation and the spread of germs.

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3. Causes congestion 

Using a fan can help you reach your ideal temperature for quality sleep. But all that air can dry your nose, mouth, and throat. Your body may produce excess mucus to make up for the dryness. And the overproduction can lead to symptoms, such as:

• Stuffy nose (nasal congestion)

• Burning or itching sensation in your nose 

• Nosebleeds 

• Sinus headache 

• Dry, sore throat 

• Coughing 

4. Dries your skin and eyes 

A fan's steady stream of cool air can also dry your skin and eyes. This possible side effect may be particularly uncomfortable if you have eczema, psoriasis, dry eye, or other conditions that affect your skin and eyes. 

Can you lower the risk of side effects caused by the fan?

Yes. Several methods may lower the risk of side effects of sleeping with a fan on. So, before you give up your fan altogether, consider these tips:

• Keep your home clean. This might lower the chance of allergies or asthma flare-ups. Vacuuming, dusting, and other cleaning tips can help prevent allergens and other unknown particles from swirling in the air. And remember to clean your fan since the blades can collect dust.

• Use an air purifier. Consider buying an air purifier with a high-efficiency particulate air (HEPA) filter for your bedroom. Experts recommend HEPA filters to limit the spread of dust mites, pet dander, and other irritants that trigger allergies.

• Try a dehumidifier. Like dry air, humid air can pose risks for your allergies or asthma. Dust mites, mold spores, and mildew thrive in moist environments. Dehumidifiers remove excess moisture from the air and can help keep indoor air pollution at bay and reach target humidity levels in your home.

• Set a timer. If your fan has a timer, try setting it for 1 to 2 hours after you go to bed. That way, you can keep the room cool while you fall asleep but stop dry air from flowing all night. This simple step could also lower the risk of drying your skin, eyes, and sinuses up.

• Turn on your fan's oscillating feature. Many standing fans include an oscillating feature. They rotate side to side to make sure that air circulates in different directions. The even airflow will prevent too much dry air from hitting you directly. 

• Keep your fan at a distance. If you have a floor or standing fan, try keeping it a few feet away from where you sleep. This setup will help manage the temperature in the room without blowing a strong breeze directly on you. 

Can sleeping with a fan on make you sick?

If you’re generally healthy and you don’t have allergies, sleeping with a fan on shouldn’t make you sick. But if you’re sensitive to things like dry air and dust, sleeping with a fan on can worsen your symptoms. This is because a fan can increase circulation of some of these indoor allergens. 

People with asthma or allergies to indoor triggers like dust and mold might find that their cough or congestion is worse after sleeping with a fan on. So it’s important to pay attention to how you’re feeling when you wake up after a night with the fan on. If you find yourself more congested or coughing more, you might want to look at other options for staying cool at night. 

Other ways to stay cool at night

Remember that there are plenty of other ways to stay cool at night. Here are some tips to help you stay cool without a fan:

• Use blackout curtains and keep them closed during the day. This helps prevent heat from entering the room and can make your nights cooler and more comfortable. 

• Consider buying a cooling mattress. Some mattresses have built-in technology to make sure your body stays colder at night.

• Take a warm bath or shower before bedtime. Studies have shown that a warm bath or shower 1-2 hours before bedtime can help you fall asleep faster by lowering your core body temperature.

• Don’t exercise before bed. Exercise increases body temperature so you’ll feel more body heat as you’re trying to settle into sleep. 

• Drink a small glass of ice water before bed. This can cool you down but don’t drink so much that you have to wake up in the middle of the night to pee. 

• Don’t drink alcohol before bed. Alcohol can make you sweat more and feel more hot, so it’s best to avoid it shortly before sleeping.

• Switch to light sheets and bedding. And make sure to wear light, loose-fitting pajamas to minimize sweating and heat. 

• Open the window a little. Depending on your environment, it may be easier to crack open the window and let the natural cool air come into the room. 

• Consider turning on the air conditioner.

Is it better to sleep with a fan or air conditioner?

The decision to sleep with a fan or air conditioner depends on several important factors. These include your medical history, dry air sensitivity, indoor air quality, and personal preferences. 

Both fans and air conditioners can help you beat the heat. But, they do so in different ways. The former circulates air to help you stay cool. And the latter cools the air to lower the temperature in your environment. Unlike fans, air conditioners also help filter the air and keep humidity levels steady. So they may be a better choice if you have asthma or certain allergies. 

But keep in mind that older air conditioning systems may not ventilate the air well enough. Interestingly, running an attic or window fan can help improve ventilation and air quality if you do have an older system. 

That said, air conditioners use a lot of energy and can be costly. So fans might be a better, more energy-efficient choice on less humid days. Both fans and air conditioners are effective cooling methods. And no matter which one you choose, keeping indoor pollutants to a minimum is critical. So, make sure your living space is clean and well-ventilated. 

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Written by:

Jennifer Clements, MD, MSEd, NBHWC

Jennifer Clements, MD, MSEd, NBHWC, is a board-certified physician and health coach who is passionate about achieving optimal health through healthy lifestyles. Clements is a diplomate of the American Board of Obesity Medicine and the American Board of Integrative Medicine.

Edited by:

Alex Eastman, PhD, RN

Alex Eastman, PhD, RN, is a California-based registered nurse and staff medical editor at GoodRx, where he focuses on clinical updates and Latino health.

Reviewed by:

Karen Hovav, MD, FAAP

Karen Hovav, MD, FAAP, has more than 15 years of experience as an attending pediatrician in a variety of clinical settings. She has worked in a large academic center in an urban city, a small community hospital, a private practice, and an urgent care clinic.

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