Cold water and AC do not have viruses. Then why do you get sore throat if you drink ice water or sleep under AC? Doctor explains: 'Cold water doesn't...'

Why does sleeping in an air conditioned room or drinking cold water, trigger a sore throat, if they are caused by viruses or bacteria? Taking to X, internal medical expert Dr Priyam Bordoloi explained the phenomenon. He stated that on their own, cold water and AC does not have respiratory viruses. However, temperature upheavals does affect your body’s response to infections.

Exposure to icy drinks or very cold air from an air conditioner can trigger an immediate response in the throat. The tiny blood vessels lining the pharynx narrow to reduce heat loss and help maintain body temperature. As circulation decreases in that area, fewer infection-fighting white blood cells reach the throat, temporarily lowering the level of immune surveillance.

Air conditioners and fans also reduce humidity in the surrounding environment, which can dry the lining of the nose and throat. Under normal conditions, the moist mucus coating the respiratory tract acts as a protective barrier by trapping harmful germs and particles before they can invade the body. When this layer loses moisture, its ability to block pathogens becomes less effective, leaving the throat more susceptible to irritation and infection.


Another important medical fact is that the upper respiratory tract naturally contains small numbers of bacteria and viruses, even in healthy individuals. These microorganisms usually coexist without causing illness because the immune system continuously keeps them under control. However, when cold temperatures and dryness temporarily weaken the throat's natural protective mechanisms, these microbes can reproduce more quickly and increase the likelihood of triggering an infection.

The key point is that consuming cold water or being exposed to chilly air does not directly introduce viruses into the body or create an infection on its own. Instead, the combination of lower temperatures and reduced moisture can briefly weaken the throat's local immune defenses, making it easier for microorganisms that are already present to multiply and cause symptoms such as a sore throat or respiratory illness.