You blast it near your sweaty body to try and cool down, but according to a sleep advisor; it might not be such a great idea.
Sleeping with a fan on full blast might help to cool you down, but it could also trigger some other issues that are just as annoying as sleeping in your own sweat.
According to a sleep advisor, the fan circulates air and anything in that air like pollen and dust. So if you struggle with hay fever- the fan could actually trigger those itchy eyes and throat and running nose.
The expert also warns that fans blowing on your skin and cause irritation and pimples. That constant blast of cool air on your skin may feel refreshing, but it can also strip your skin of moisture. If your skin is dry, dirt and sweat can cause that irritation or zits!
The Sleep Advisor also points out that having the fan on all night could even leave you with aches and pains in the morning, as the cool air causes your muscles to tense up and cramp.