教师和学生长时间用脑后,常常会觉得头晕脑胀,记忆力降低,非常疲劳。有的人喜欢用冷水浇头,以为这样就能清醒头脑,提高工作和学习效率。殊不知这对身体健康是有害的。人从事脑力劳动的时候,大脑需要血液输送充足的氧气和营养物质。用脑时间过长,营养消耗增加,血液循环不足,就会觉得头晕、疲劳。这时候如果用冷水浇头,血管会剧烈收缩,血流减慢,使脑子得到 Teachers and students spend a lot of time behind the head, often feel dizzy, memory loss, very tired. Some people like to use cold water toppings, thinking that this will be able to clear your mind, improve work and learning efficiency. As everyone knows it is harmful to health. When people are engaged in mental work, the brain needs adequate oxygen and nutrients in the blood. Brain time is too long, increased nutritional consumption, lack of blood circulation, you will feel dizzy and tired. At this time if you use cold water toppings, blood vessels will be sharp contraction, slowed blood flow, so that the brain can be