At the same time, the capillaries on the skin surface dilate, sweat and cool down. At this time, if the air conditioner or fan is blown, the normal structure of the body will be broken. Not only can not achieve the effect of fitness, but it is harmful to yourself, from catching a cold to causing capillaries to rise! This is unscientific. You should use natural cooling. When your heart rate is stable, you won't feel hot naturally.