After fitness, the human body produces heat and sweats a lot. At this time, it is best not to take a bath. Cold water can quickly reduce the body surface temperature, causing stress reactions of the human body, such as skin contraction and muscle trembling, which can seriously cause cramps, seriously affect the immune system, lead to decreased resistance, and even diseases such as colds and pneumonia. Therefore, it is better to take a hot bath as much as possible after fitness.