What is ‘air con flu’? How staying cool may make you sick

Keeping cool can make you sick.

If you’ve ever felt a sniffle coming on in the summer months — particularly when you’re on vacation — then air conditioning could be to blame.

The phenomenon has been widely documented on TikTok, with a few different names coined for the illness, such as “Ayia Napa Flu,” “Air Con Cough” and “Magaluf Flu.”

But what is it, and is it a real illness?

According to a 2004 study in the Journal of Epidemiology, there is some science to support “air con sickness.” Researchers found that being in air conditioning — if the unit has not been maintained or is in a poorly ventilated building — can cause health problems.

Working or living in a poorly ventilated building with air conditioning can raise your risk of “sick building syndrome,” a term used to describe collective symptoms experienced by a building’s occupants, according to the EPA.

Symptoms may include headaches, dry cough, dizziness, nausea, trouble concentrating, fatigue and odor sensitivity.

Science ABC reported that when air conditioners are not properly maintained or cleaned, they are potentially filled with bacteria and mold. This can mean that the unit may circulate infected air.

Heating, ventilation and air conditioning units are designed to filter air pollutants and contaminants from indoor air, however, if the filters are not cleaned properly they become prime space for air particles and microorganisms to breed. This may trigger asthma, allergies and other respiratory symptoms. 

“Dirty air conditioning filters may be contaminated with mold, fungus or other microorganisms,” a representative for the California Department of Public Health told Verywell. “This may lead some occupants, especially if sensitive to molds, to have breathing problems.”