Medical experts have proved that the human foot is the farthest part of blood vessel branch, and the fat layer of the foot is thin, the heat preservation is poor, and the skin temperature of the foot is low, which is the part with the lowest body temperature. If you often wash your feet with cold water in summer, it will further make your feet cold, and then cause a series of complex pathological reactions through vascular conduction, which will eventually lead to diseases. In addition, because Hanquan with low feet is relatively developed, suddenly washing with cold water will lead to the sudden closure and blockage of pores, which will lead to the slow perspiration function over time. In addition, the sensory nerve of the foot will be stimulated by cold water, and the normal vascular tissue will contract violently, leading to vasodilation dysfunction and inducing arterial spasm, erythematous limb pain, arthritis, rheumatism and so on.
The temperature of shampoo is 3 1 ~ 38℃. Too hot water can easily damage hair, making it brittle and easy to break. If the water is too cold (cold), the oil stain removal effect will be poor and the washing will not be clean. When changing water, the water mixture used successively should be roughly the same, and it is not advisable to cool before heating or heat before cooling.
It is best to use warm water, because warm water can dilate skin capillaries and superficial dermis blood vessels, open sweat pores and promote the excretion of metabolic wastes, so it has stronger decontamination power than cold water, especially the dirt attached to hair shafts is easier to remove.
If you wash your hair with cold water in cold winter, it will also cause a cold.
Even in hot summer, the difference in head temperature can lead to diseases such as colds.
Headache caused by cold water washing in hot weather
Many people like to wash their hair with cold water when sweating in hot weather, which can easily cause headaches. Because people's intracranial arteries and blood vessels are very sensitive to pain, in the hot season, the head is prone to sweating after exercise. At this time, the blood vessels dilate. If washed with cold water, it may cause abnormal intracranial vascular function, dizziness, blackness in front of eyes, vomiting and other symptoms, and even cause intracranial hemorrhage in severe cases. Therefore, you must wash with warm water after a lot of exercise, and the elderly with cardiovascular and cerebrovascular diseases should pay more attention.