We must pay attention to the following questions in winter health preservation: 1, the best time for health preservation. Experiments show that the biological clock is at its peak at 5-6 am and the body temperature rises. At this time, you will get up fresh. 2. Keep warm. Listen to the weather forecast on time and add clothes and warm-keeping facilities with the change of temperature. Soak your feet with hot water 10 minutes before going to bed, and the room temperature should be suitable. Under the condition that the air conditioning temperature should not be too high, the indoor and outdoor temperature difference should not be too large, and the indoor and outdoor temperature difference should be 4-5 degrees. 3. The best time to keep fit. Experiments show that 5-6 am is the climax of the biological clock, and the body temperature rises, so it will be healthier to get up at this time. 4. It is best to open the window at 9- 1 1 every morning and at 2-4 pm for ventilation. 5. Don't exercise casually in the morning. Not too early. Many people choose to do morning exercises before or at dawn (around 5 o'clock), thinking that the environment is quiet and the air is fresh. Actually, it's not like this. Because of the cooling effect of the air near the ground at night, it is easy to form a stable inversion layer, just like a cover that covers the air, making it difficult for pollutants in the air near the ground to spread, and the pollutant concentration is the highest at this time. Therefore, morning exercisers should consciously avoid this period of time and choose after sunrise, because after sunrise, the temperature begins to rise, the anti-atmosphere is destroyed and pollutants spread out. This is a good opportunity for morning exercise. 6. Never choose a forest. Many people think that when doing morning exercises in the Woods, there is enough oxygen to meet the demand for oxygen during exercise. But this is not the case. Because the chlorophyll of plants can only be photosynthesized with the participation of sunlight, producing fresh oxygen and releasing a lot of carbon dioxide. Therefore, green trees are a good place for walking during the day, but not an ideal place for exercise in the morning. 7. Middle-aged and elderly people should not do morning exercises. Because the middle-aged and elderly people have diseases such as myocardial infarction, ischemia and arrhythmia, the peak of the disease appears in the morning to noon within 24 hours a day. If you exercise during this period, especially in the early morning, it will induce serious accidents such as heart rate disorder and myocardial ischemia, and even lead to catastrophic consequences of sudden death, while exercise from afternoon to night is rare. 8. Drinking water Because I didn't drink water all night, my blood was sticky in the morning, which increased the risk of blood vessel blockage. After getting up, the sympathetic nerve excitability increases, the heart rate accelerates, and the heart itself needs more blood. 9- 10 in the morning is the time when blood pressure is the highest in a day, so the morning is the most frequent time for stroke and infarction, which is called devil's time in medicine. Drinking a cup of boiled water after getting up early can replenish body moisture and gastric lavage. A glass of water an hour before meals will hinder digestion and secretion and promote appetite. 9. Sleep. The body's "biological clock" has a low tide at 22-23, so the best sleep time should be 2 1-22.