Here’s Why You Should Never Run Your Fan or A/C All Night – Maine, New Hampshire, & Massachusetts Take Note

For the first time in 2025, much of New England is facing sweltering temperatures.

Yes, there have been a few warm days in New England this spring, but this is the first time this year that we have had to deal with temperatures in the upper 90s or lower 100s.  On top of that, it is the first time that we have seen truly oppressive humidity.

Because of the temperatures, many people are running their air conditioners 24-hours a day.  Those who are not fortunate enough to have an air conditioner are probably running a fan all night long.

Many experts say that is not a good idea.

Why?

Why is it a Bad Idea to Run Your Fan or A/C All Night?

According to an article on the Mattress Next Day website, there are several really good reasons why you should not be running your fans or air conditioners all night.

1 - Using a fan or A/C can trigger allergens - While the breeze from a fan may cool you down, it is also likely to blow dust, pollen, and dust mites around your room.  When you breathe these in, it can trigger a reaction.  Fans are the main culprit of this, but A/Cs do still blow things around your room.

2 - They can make you congested - Both fans and air conditioners can dry out the air.  This can lead to your nose drying out causing you to become congested.

3 - They can lead to dry eyes - In the same way that they can cause congestion, fans and air conditioners can lead to dry eyes.  Overall, air conditioners are a bigger cause of this than fans.  Part of the 'conditioning' that A/Cs do is eliminating moisture from the air.

4 - Nighttime coughing - That same dry air can cause you to have a coughing fit in the middle of the night.

5 - Sore muscles - Having cold air blown on you can cause muscle aches.  Clearly, an air conditioner is more likely to do this to you than a fan.

The Dangers of Hot Weather

Clearly, don't put yourself at risk for heat stroke because you don't want dry eyes or muscle aches.

If it is dangerously hot in your bedroom, please continue to run your air conditioner or fan.  It is better to have a dry nose, a bad case of allergies, or a muscle ache in your arm than it is to die from the heat.

Fortunately, here in New England, we only get a few weeks of hot weather.

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