Letting air conditioning and electric fans blow directly into your face: A habit you need to quit immediately

During the recent hot weather, I have a habit of turning on the fan and air conditioner immediately after coming home from the sun, even setting the temperature down to 16 degrees Celsius. The cool feeling is like “summer cooling” for the body, but afterwards I often feel tired. Is this symptom due to the harmful effects of sudden temperature changes? Thank you for your advice, doctor. (Nguyen Thi Hang - Long Bien, Hanoi).

Doctor Nguyen Huy Hoang - Vietnam - Russia High Pressure Oxygen Center, Ministry of National Defense, advises:

Hot weather is when the ambient temperature is 33 degrees Celsius or higher, when the body begins to sweat. When it is hot, people often have the habit of moving from hot and sunny places to cold places suddenly. The feeling of coming back from the sun or having a power outage and then being exposed to a very cold environment, blowing wind on your face at home or in the car helps you "wake up" but this is extremely harmful to the body, causing blood vessels to constrict or dilate.

Normally, on hot days, the body faces many dangers such as excessive sweating, blood thickening and a higher risk of blood clots leading to many risks of cardiovascular disease. In addition, hot weather often causes the body's electrolytes to be disrupted, increasing nerve conduction and myocardial contraction, affecting the transmission of blood from the heart to nourish other parts of the body.

Specifically, the 3 most common harmful effects you encounter when you have the habit of turning on the fan or air conditioner directly at low temperatures:

Firstly, when the air conditioner or fan blows on the body, it dries the skin very quickly, causing the electrolyte concentration in the body to change, affecting nerve conduction.

Second, the thermoregulatory center, especially in the elderly and children, does not function as well as in young adults. If these people are exposed to a cold environment immediately, it can cause vasoconstriction, which can lead to stroke or myocardial infarction. In addition, the thermoregulatory mechanism does not work in time, which can cause colds and excessive hypothermia.

Third, when the temperature changes too suddenly, the skin, nose, and eye mucosa tend to constrict blood vessels, the mucosa dries out... the protective immune cells in the body decrease, resistance is weakened. The dry mucosal surface is more susceptible to colds and sore throats. The cause is from external bacteria or bacteria that exist in the nose, throat, and mouth. Blood vessels constrict, the mucous membrane dries out, and bacteria and viruses become more active, causing respiratory infections.

Therefore, you should not set the air conditioner temperature too low. The theoretical optimal temperature difference is 7 degrees Celsius. However, when the temperature reaches 40 degrees Celsius, this temperature difference still causes heat. Therefore, you should only set the temperature at 28 degrees Celsius. If you use an electric fan, you should also keep it far away and not blow the fan directly into your face when sleeping.

When you come back from hot weather or when the power is out and the power comes back on, you should not immediately turn on the fan or air conditioner at the coolest setting. You need to let the temperature change slowly.

For the elderly, children, and people with underlying diseases, if you are outside in the heat, sweating, and losing water, you should slowly replenish water and dry your sweat before entering a cold room or an air-conditioned car. Most dangerously, people with high blood pressure, if the temperature changes suddenly, can lead to a stroke.

In the current hot weather, for the elderly and children, it is necessary to maintain hygiene, especially the respiratory tract to avoid diseases caused by microorganisms. It is recommended to gargle with saline solution every day. At the same time, everyone needs to have a reasonable diet and should limit fried foods and take adequate vitamins./.