In recent days, there has been a large temperature difference between day and night. Several doctors remind citizens not to blindly reduce clothing or cover excessively to reduce the risk of diseases. Especially for key populations such as the elderly and children, it is necessary to keep warm scientifically. Winter and spring change seasons, and it gets cooler in the morning and evening. Zhao Xin, Deputy Chief Physician of the Sub Health Department at Dongfang Hospital of Beijing University of Traditional Chinese Medicine, said that during sudden changes in temperature, the pores of the human body open, making it easy for external pathogens to invade the body. Cold can also cause poor circulation of qi and blood, leading to symptoms such as fear of cold and cold hands and feet. The temperature regulation center of children is not yet fully developed, and their ability to adapt to temperature changes is poor. At the same time, they have a high level of daily activity and are prone to sweating. When sweat is not dry, they are easily exposed to cold air and are prone to catching a cold. In addition, elderly people have lower immunity, poor temperature regulation ability, weaker respiratory mucosal defense function, and are more susceptible to virus and bacterial invasion. Tian Rong, Deputy Director of the Respiratory Department at Beijing Geriatric Hospital, said that catching a cold may trigger colds, coughs, and worsen underlying diseases such as chronic obstructive pulmonary disease and asthma; Causing blood pressure fluctuations and increasing the risk of cardiovascular and cerebrovascular diseases such as hypertension and coronary heart disease; Exacerbating joint discomfort. Timely and appropriate adjustment of clothing is the core of keeping warm during seasonal changes. Especially for the elderly, do not take off cotton jackets and long johns too early. You can adopt the "onion style" dressing method, which means choosing breathable cotton for the inner layer of clothing, keeping the middle layer warm, and the outer layer windproof, making it easy to put on and take off at any time. Zhao Xin suggests that the focus should be on keeping the head, neck, chest, back, and feet warm. Wear comfortable cotton socks on a daily basis to keep the feet warm. Elderly people can wear thin hats and scarves to reduce cold stimulation of cerebral blood vessels; Children should prepare an extra shoulder brace to protect their back and abdomen, preventing them from getting cold, abdominal pain, and diarrhea. She reminded parents to pay special attention to keeping their preschool children warm. "Children cannot judge whether they are warm or cold independently and will not actively add or remove clothing. Parents can use the method of 'touching the back of the neck' to judge whether their children are hot or cold. The back of the neck and back should be warm and sweat free, which is the standard for dressing just right