Washing your hair at night is harmful to health

As we know, the pace of modern life is very intense. People are busy with their work, activities and entertainment during the day. Therefore, they like to wash their hair at night when they are free.

Of course, it’s okay if you have enough time for your hair to dry when you wash your hair at night. But sometimes you are too busy to wash your hair before 10 pm and you feel so tired after washing that you always go straight to bed and sleep before your hair is completely dry. To do so, the elders will say that it will cause you a headache later. In fact, his words are somewhat reasonable through modern scientific research.

We must know that the human body always continuously produces heat in the process of metabolism to maintain body temperature. And the heat would be transferred to the superficial layer of the organism through the blood circulation and would be emanated towards the outside through forms of radiation, conduction, convection and evaporation.

For those with strong body resistance and normal regulation function, the two processes of heating and cooling are in balance, that is, the heat will increase when the body temperature decreases, making the body temperature stay around 37 C. But for people who have weak body resistance and poor body temperature regulation function, they are easy to cool down by full or local exposure to cold.

After washing the hair with lukewarm water, the capillaries in the scalp will dilate due to the warming effect and the radiating body heat around will increase. Meanwhile, wet hair will cause a lot of water to evaporate, taking a lot of heat out of it. Generally speaking, 500 calories will be lost when one gram of water evaporates.

As heat loss increases and the body cools, the upper airway capillaries reflexively shrink, the volume of partial blood flow is reduced, and the upper airway resistance decreases, leading to existing viruses or bacteria have a chance to intervene. , grow and reproduce. It will result in respiratory tract infections, which cause people to have flu-like symptoms, such as a runny nose, nasal congestion, headache, or fever.

In general, you should avoid washing your hair before going to bed. Even if you had to do that, you should towel dry your hair. This way you won’t catch a cold.