天热人就会出汗。炎夏成人一天可排出汗液1000毫升左右,紧张劳动时可出汗2000～6000毫升。汗不是普通的“水”,里边含有0.2～0.5%的盐(氯化钠)。所以,大量出汗,既失水又失盐。这时如果不及时补充水和盐,人体的水盐代谢紊乱,人就会无力、恶心,甚至抽筋(以小腿抽筋常见),这就叫“热痉挛”病。为了防止发生热痉挛病,防暑茶里要放点盐。如果出汗多的人喝没盐的白水,还有害 Hot days will sweat. Summer adult sweat can discharge about 1,000 ml a day, when labor can be sweating 2000 ~ 6000 ml. Sweat is not ordinary “water”, which contains 0.2 to 0.5% salt (sodium chloride). Therefore, a large number of sweating, both water loss and salt loss. At this time if you do not add water and salt in time, the body’s water and salt metabolism, people will be weak, nausea, and even cramps (to the leg cramps common), which is called “hot cramps” disease. In order to prevent the occurrence of hot spasms, sunstroke tea to put some salt. If you sweat and drink salt and white water, but also harmful