"Waterproof Cooling Fan" to open the wind speed should not be too large, so that the human body has a process of adaptation. Indoor wind speed is best controlled at 0.2-0.5 m / sec, especially in ventilated rooms and in places, fans of the wind speed but can not be too large. Fans should not be facing the person blow, direct blow, invade the body, especially in frail or sweating, it is best to let "Waterproof Cooling Fan" in one corner of the blow. Children, elderly, frail people, but should use less fan blowing, but can be "Waterproof Cooling Fan" regulate indoor air, thereby indirectly cooling. When the dripping sweat but can not direct access to fan blowing, so as not to cause surface perspiration disorders, leading to destruction of the human circulation, it is easy to cause a stroke.