As summer nights grow warmer, many households in the UK are trying to stay cool—especially since only about 5% of homes are equipped with air conditioning. For most people, the solution is simple: switch on an electric fan. It’s an easy, cost-effective way to circulate air and provide some relief when temperatures climb. But is it completely safe to sleep with a fan running all night?

According to Dr. Naheed Ali, a health expert, the answer is not as straightforward as it seems. While fans may help you feel cooler, they could also bring on a few unwanted side effects if used improperly, especially while you sleep.

Hidden Health Risks of Sleeping with a Fan

1. Dry Throat and Sinuses
One of the most common issues with sleeping next to a fan is the drying effect of continuous airflow. When a fan blows directly on you all night, it can lead to dehydration in your respiratory system. That dry air can cause your throat, nasal passages, and even your eyes to become irritated.

As your airways dry out, your body may respond by producing thicker mucus, which can lead to morning congestion or a scratchy voice. Many people wake up with a persistent cough or discomfort in the throat and sinuses that lingers throughout the day.

2. Worsening of Allergies or Asthma
Fans do more than just move air—they also move particles. If there’s dust, pet dander, pollen, or lint in the room, the fan can stir these allergens into the air and circulate them throughout the night. For individuals with allergies or asthma, this can be a real problem.

Breathing in airborne irritants while sleeping can lead to sneezing, nasal congestion, or even tightness in the chest. Instead of waking up feeling refreshed, you may find yourself more congested or wheezy than the night before.

3. Muscle Stiffness
If you’ve ever woken up with a sore neck or stiff shoulders after sleeping with a fan on, you’re not imagining things. Constant exposure to cool air, especially if the fan is pointed directly at you, can cause muscles to tense up. Your body responds to the cold airflow by contracting muscles in an effort to retain heat.

This can result in stiffness and discomfort in the neck, shoulders, or back the next morning—especially for those who sleep in one position all night.

How to Use a Fan Safely While Sleeping

Despite these risks, fans can still be a useful and safe tool for better sleep—if you use them correctly. Dr. Ali offers a few helpful tips to keep you cool without putting your health at risk.

1. Use a Timer
Instead of letting the fan run all night, try setting it to turn off automatically after the first 60 to 90 minutes of sleep. This helps your body cool down enough to fall asleep comfortably without prolonged exposure to dry or cold air. Many modern fans come with built-in timers, or you can plug them into a smart outlet for even more control.

2. Avoid Direct Airflow
It might feel good to have a fan blowing right on your face when you’re hot, but that direct airflow is what leads to muscle stiffness and dry sinuses. A better approach is to angle the fan toward a nearby wall or corner of the room. This creates a more indirect circulation of air, cooling the room without targeting your body.

3. Stay Hydrated
Even with moderate fan use, it’s important to keep your body hydrated. Keep a glass or bottle of water by your bedside, especially if you tend to wake up with a dry mouth or throat. Staying hydrated can help offset the drying effects of moving air.

4. Limit Allergens in the Room
Since fans tend to circulate dust and other particles, reducing the amount of allergens in your bedroom is key. Wash your bedding, including pillowcases and sheets, at least once a week in hot water. If your fan has a filter or if you use an air purifier alongside it, make sure to clean or replace the filter regularly to keep allergens under control.

The Bottom Line

Fans are a great way to make hot nights more bearable—especially in homes without air conditioning. But if you’re waking up with congestion, stiffness, or an itchy throat, it might be time to rethink how you’re using your fan.

By making a few small adjustments—like using a timer, avoiding direct airflow, and minimizing allergens—you can still enjoy the cooling benefits of a fan without putting your health at risk. As with many things in life, balance is key. Fans can help you sleep better, as long as you use them wisely.