In order to guide the public to scientifically respond to cold waves, enhance self-protection awareness, and reduce the potential health damage caused by cold wave weather, the National Bureau of Disease Control and Prevention organized experts from the Environmental Institute of the Chinese Center for Disease Control and Prevention to develop the "Cold Wave Public Health Protection Guidelines" based on the characteristics of cold waves, in order to provide protection suggestions for different key populations and maximize the protection of public health. The Guide consists of five parts: basic concepts of cold waves, health risks, key protected groups, cold wave meteorological warning information, and a guide for graded protection measures for cold wave warnings. The basic concepts and health risks are mainly introduced in two parts, which focus on the definition of cold waves and their impact on the health of multiple systems such as respiratory, cardiovascular, and urinary systems in the human body. The key protected groups pointed out the key groups that need to be paid attention to during cold waves, including sensitive populations, people with chronic basic diseases, and outdoor workers. Cold wave meteorological warning information guides the public to scientifically understand cold wave forecasting and warning information. The guide for graded protection measures for cold wave warning targets key populations and proposes targeted protection measures. Guidelines for Public Health Protection during Cold Wave 1. Basic Concept of Cold Wave Cold wave refers to the large-scale movement of cold air from high latitudes towards the center A weather activity that causes severe cooling due to low latitude invasion (according to the standard of "Cold Air Level" GB/T 20484-2017, a cold wave refers to a daily minimum temperature with a cooling amplitude greater than or equal to 8 ℃ within 24 hours, a cooling amplitude greater than or equal to 10 ℃ within 48 hours, or a cooling amplitude greater than or equal to 12 ℃ within 72 hours, and causes the daily minimum temperature in the area to drop to 4 ℃ or below, and a continuous decrease in the daily minimum temperature within 48 hours and 72 hours). 2、 Cold wave health risks: A decrease in temperature can cause vasoconstriction and increased respiratory rate in the human body. During the cold wave period, cold weather can easily cause superficial skin damage and form chilblains, exacerbating the pain of patients with arthritis, rheumatoid arthritis, and other conditions. Easy to induce airway spasm, abnormal respiratory immune function, causing acute exacerbation of chronic obstructive pulmonary disease, acute attacks of bronchial asthma, acute respiratory infections and other respiratory diseases. Easy to cause cardiovascular and cerebrovascular diseases, such as angina, myocardial infarction, arrhythmia, acute heart failure, transient cerebral ischemia, and stroke. At the same time, it may aggravate the diseases of urinary system and endocrine system, such as chronic kidney disease, diabetes, etc. 3、 There are mainly three types of key protection groups: the first type is sensitive groups, such as infants and young children, children, pregnant women, elderly people, etc; The second category refers to the population with chronic underlying diseases, such as cardiovascular and cerebrovascular diseases, respiratory system diseases, etc; The third category is outdoor workers, such as traffic police, sanitation workers, construction workers, couriers, delivery drivers, etc. 4、 According to the "Cold Wave Warning Signals and Defense Guidelines", the cold wave meteorological warning information is divided into four levels. 5、 We propose graded crowd protection measures based on the level of cold wave warning signals, as indicated by the compass for graded protection measures. (Shen Shaotie) (Le Xin She)