Nighttime fan use: cooling benefits, allergy risks, and how to use safely

Using a fan at night can help you cool off by moving air, but concentrated airflow can irritate allergies and dry the nose, throat, and skin and may cause neck stiffness or congestion. To minimize issues, oscillate the fan or point it away from you, keep room humidity at 30–50%, clean the fan and HVAC filters, vacuum to reduce dust, and consider saline nasal spray if you experience dryness. Overall, it’s unlikely to cause long-term harm when used with precautions.