Sleeping with a fan can bring comfort on hot nights, but it may also affect throat and respiratory health. Constant airflow dries out the air and your mucous membranes, leaving you with a scratchy throat in the morning—especially if you sleep with your mouth open or have nasal congestion.
Direct cool air on your face can also reduce circulation, increasing the risk of irritation, hoarseness, or mild infections. Fans may stir up dust, pollen, or mold, and dirty blades can spread allergens and germs into your breathing zone.
To minimize problems, position the fan away from your face, use a timer, add humidity, clean blades weekly, and stay hydrated.