Summer has arrived, bringing peak heatwaves with temperatures above 30 degrees C. To conserve energy, many people opt to use only a fan for cooling while sleeping instead of air conditioning. However, sleep experts warn that running a fan all night may not necessarily lead to better sleep. On the contrary, this habit can cause frequent awakenings in the middle of the night, leave you feeling exhausted the next day, and even worsen symptoms of nasal congestion, dry throat, and pollen allergies.
Natalie Pennicotte-Collier, a sleep therapist and consultant at the mattress brand MattressNextDay, states that electric fans can help people fall asleep faster in hot weather. However, in the latter half of the night – when the body begins to regulate its temperature in preparation for waking up – a continuous airflow can hinder this natural process.
"What helps you fall asleep may not be what sustains optimal sleep quality throughout the night", Pennicotte-Collier emphasized.
The expert further explained that while a fan can help you drift off quickly, as night temperatures drop towards dawn and the body's core temperature shifts before sunrise, the same fan can fragment your sleep. At this point, the body has to work harder to regulate its temperature, leading to lighter sleep.
Many mistakenly believe that maintaining a low temperature all night ensures better sleep. In reality, a person's body temperature rises slightly before naturally waking up. If a fan runs continuously all night, the air is constantly cooled and dried, disrupting this natural physiological mechanism. This is why many people, despite getting enough hours of sleep, still wake up multiple times in the early morning or feel exhausted the next day.
Furthermore, using a fan all night can negatively affect the respiratory tract. According to Pennicotte-Collier, a prolonged airflow dries out the mucous membranes in the nasal cavity, throat, and upper respiratory tract. In response, the body produces more mucus. As a result, users often wake up with nasal congestion and a dry throat without realizing the fan is the core cause.
The expert also cautioned individuals with pollen allergies (hay fever). A fan continuously circulating in a closed room will spread allergens like pollen and dust for seven to eight hours, leading to itchier eyes and more severe allergy symptoms in the morning.
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Running a fan all night may not necessarily lead to better sleep. Photo: Unsplash |
Running a fan all night may not necessarily lead to better sleep. Photo: Unsplash
To help people enjoy the cooling sensation from a fan while minimizing negative health and sleep impacts, Pennicotte-Collier suggests five methods:
Use the timer feature
The expert recommends using a fan to cool the room beforehand or setting it to automatically turn off after about one hour. This approach helps you fall asleep easily while preventing dry skin, dry nasal passages, and body temperature imbalance in the latter half of the night.
Do not point directly at your face
If you sleep directly in the fan's airflow, dryness and irritation around the nose, throat, and eyes will worsen. You should direct the fan towards the ceiling or a wall instead of pointing it directly at yourself or your face. This method improves cool air circulation in the room while reducing respiratory irritation.
Clean the fan more often during heatwaves
Pennicotte-Collier notes that electric fans easily accumulate dust, pollen, and micro-dust particles in summer. These agents are then dispersed throughout the room at night. The expert likens it to: "Fan blades are actually one of the most effective dust collectors in the bedroom." Therefore, individuals with pollen allergies, asthma, or dust mite allergies need to clean their fans thoroughly and regularly.
Do not open windows when outdoor pollen levels are high
While many people habitually open windows for fresh air when it's hot, Pennicotte-Collier points out that if daily pollen levels are high, opening windows at night will worsen allergy symptoms. Especially when combined with an electric fan, allergens will be continuously circulated in the room all night.
Stay hydrated
Maintaining adequate hydration helps mitigate the drying effects caused by electric fans. You should drink plenty of water during the day and can place a glass of water by your bedside before sleeping. This habit helps soothe dry and irritated throats the next morning and promotes better sleep quality.
My Y (According to UDN).
