阳历二月,我国绝大部分地区的天气特征是干燥、寒冷。此时,北方冷空气势力强大,空气干燥,雨雪较少,天气呈现持续干冷的态势。白天的平均相对湿度一般低于50%,加之室内采暖,居室内的湿度甚至只有30%左右。因此,这一时段又称“干冷时段”。干燥的气候容易使人患感冒,还会加重呼吸道疾病的症状,肺气肿和慢性支气管炎等疾病也容易复发或加重。空气干燥造成痰液黏稠 Gregorian calendar February, most of the weather in our region is characterized by dry and cold. At this point, the northern cold air powerful, dry air, less rain and snow, the weather showed continued dry and cold situation. During the day the average relative humidity is generally less than 50%, combined with indoor heating, indoor humidity or even only about 30%. Therefore, this period is also called “dry cold period ”. Dry climate easily make people suffer from cold, but also aggravate the symptoms of respiratory disease, emphysema and chronic bronchitis and other diseases are easy to relapse or aggravate. Air-dry sputum caused by sticky