What are the hazards of using electric fans in summer?

In the hot summer, people will take many ways to cool down. The most common one is to use electric fans. Especially for families with poor economic conditions, electric fans are the main way to cool down. I would like to remind everyone that there are many precautions when using electric fans in summer. For example, it is best not to use them when sleeping at night. In addition, people with weak bodies, such as pregnant women or the elderly, are not suitable for using fans. Otherwise, excessive use of fans will bring many disadvantages.

The hazards of using electric fans in summer:

When you sleep with an electric fan that blows continuously at the body, the heat on the side of the body that is blown will quickly dissipate, and the skin blood vessels and sweat glands will contract accordingly. On the other side, the skin temperature is still high, and the epidermal blood vessels and sweat glands are still dilated. Because the body temperature center has no time to adjust, it will cause physiological dysfunction of the body and cause symptoms such as dizziness, headache, fatigue, laziness, back pain, nasal congestion and runny nose.

Continuously blowing air directly into the air from an electric fan often causes dizziness, headaches, fatigue, and lack of appetite. This is because the blood supply to the area being blown is reduced, while the blood flow to other organs increases. The skin on the head is rich in blood vessels and is sensitive to cold stimuli, which can easily cause symptoms such as dizziness and headaches. In addition, due to the faster evaporation of skin moisture and the reduction of body fluids, people are prone to feeling tired and are also more likely to catch a cold due to cold. Long-term and high-volume air blowing on the head may even cause spasm and contraction of the facial nerve, followed by swelling, ischemia, paralysis, incomplete closure of the eyes, crooked mouth, and inability to frown, blow air, whistle, etc. This is "facial nerve paralysis", commonly known as "crooked mouth wind". Some people may suffer from joint pain and stiff neck when exposed to wind while sleeping. In addition, the "whirlwind" of electric fans can also have a harmful effect on the eardrum.

Improper use of electric fans can even cause sudden death. An accident occurred in a hotel in the south where a person was killed by an electric fan. After examination by the local forensic doctor, it was confirmed that the sudden death was caused by prolonged use of the electric fan. Why can electric fans kill people? This is because when air flows rapidly, the body surface temperature will drop to 24°C. After 6 hours, the following changes will occur in the human blood: hematocrit increases by 7%, the average platelet volume increases by 15%, blood viscosity increases by 21%, the average blood pressure increases from 130/70 mmHg to 138/87 mmHg, and cholesterol also increases significantly. These changes can promote the rapid formation of blood clots, which is prone to sudden myocardial infarction or cerebral thrombosis, leading to sudden death, for people who originally had no obvious symptoms but already had latent cardiovascular disease.

In order to prevent the above-mentioned hazards, the following points should be noted when using an electric fan: When using an electric fan, do not keep the head and face too close to the fan to prevent the wind speed from being too high and the skin from dissipating heat too quickly; do not use an electric fan to blow the head for a long time after taking a bath or sweating profusely to prevent the skin on the head from being excessively cold; when using an electric fan, do not blow one fixed part, it is best to turn it back and forth, so that intermittent and circular blowing will not cause the skin temperature to drop suddenly; do not use an electric fan immediately after strenuous exercise, because at this time the sweat glands are wide open and the pores are loose, and evil winds can easily take advantage of the opportunity to enter, causing a cold at the mildest and a high fever at the worst, which is harmful to human health; some people like to soak their bodies before using the electric fan. Although this can dissipate body temperature faster, it should not be done frequently, otherwise it is easy to induce rheumatoid arthritis.