Winter has passed, both north and south, and cooling temperatures followed. The latest summary of the unconscious changes that occur in the body during cold weather is presented in the American magazine Prevention. Only by understanding these, you can be more targeted and prepared for a healthy winter. Change 1: shivering cold wind, the whole body muscles will tighten up. Cold sensory receptors excited, into the thermoregulatory center, will cause involuntary rhythmic contraction of skeletal muscle, the purpose is to convert mechanical energy into heat, to relieve the cold. This is medically known as “shivering thermogenesis”. Stamping your feet in the cold wind is also an instinctive reaction based on this principle. Change 2: Cold at the end of the body When the outside temperature is low, more blood will flow to the center of the body to supply oxygen and nutrients to vital organs, and the end parts of the body such as fingers, toes and ears will feel cold due to reduced blood flow. Therefore, when you go out, you should put on ear muffs or cover your ears and nose with a wide hat or scarf; wear thick socks and warm shoes, and bring gloves; and wear warmer clothes on your chest and back to help distribute blood flow evenly and protect the blood supply to the body’s periphery. The elderly, children and other frail people should pay particular attention to keeping their limbs warm. When you enter a warm room from outside, rub your hands and then your ears to warm them up quickly, not directly with hot water or hot objects. Change 3: Runny nose Normal people secrete hundreds of milliliters of nasal snot every day, they will follow the direction of nasal mucous membrane cilia movement, flow to the posterior nasal orifice, and then to the pharynx, and another part evaporates or dries up, so usually there is no snot flowing down. However, when cold air enters the nasal cavity, capillaries contract and cilia movement is weakened, and the phenomenon of clear nasal discharge or nostril mucus will appear. This is a self-protective reflex of the nose sensitive to cold air. Wearing a mask on cold days can reduce the chance of cold air entering the nasal cavity. Washing your face with cold water once a day can enhance your ability to adapt to the cold. When you have a runny nose, you can rinse your nose with warm salt water and massage your nose at the same time. If the slightly cold air is constantly runny nose and lasts for a long time, and it does not get better when you go indoors, you should suspect that it is caused by rhinitis, and it is recommended to go to the hospital for consultation. Change 4: Increased burden on the heart In the cold, in order to supply energy to the body, the heart rate will increase, and the oxygen consumption and workload of the heart will also increase. Blood is more viscous and flows more slowly at low temperatures, which further increases the burden on the heart. Once stimulated by cold, the coronary arteries tend to contract and spasm, blood pressure rises, and patients with pre-existing underlying cardiovascular pathology may experience acute myocardial ischemia, triggering angina pectoris and even myocardial infarction. To reduce the risk, it is recommended that: first, turn up the bathroom temperature before bathing to avoid cold stimulation; soak your feet in hot water before going to bed to promote blood circulation. Second, drink more water, eat more fruits and vegetables, and eat less large fish and meat to reduce blood viscosity and avoid blood clots. Third, pay attention to the details of life, such as a slower change of position, do not quickly get up. Fourth, pay attention to the heart “cold” warning signs. For example, sudden pain or pressure on the left side of the chest during exertion; sudden panic and palpitations, blackness in front of the eyes, a sense of falling; shortness of breath, a long exhalation or breathlessness; sudden awakening during sleep, chest tightness, breathlessness, etc. Change 5: Shortness of breath Walking against the cold wind sometimes makes you breathless, coughing, nauseous and want to vomit. This is because the cold dry air will make the nose dry, stimulate the throat area, but also make the small airways contraction, so that the respiratory stress response. Winter out to protect the oropharynx, try to breathe through the nose to avoid cold air; usually pay attention to hydration, no less than seven or eight cups a day, honey water has a moistening function; eat more pears, silver fungus, lilies and other lung food; home can use humidifiers to keep the humidity constant. Change 6: urinate more frequently urine Each person’s water intake does not change much in the four seasons, winter sweat evaporation is reduced, the amount of urine will increase accordingly. Cold will also stimulate the nerve center, causing changes in the regulation of the endocrine system, increasing the amount of urination. In order to protect against the cold, most organs, including the bladder, will show a state of contraction, but also more likely to urinate frequently. In winter, it is important to avoid cold in the waist and abdomen; ensure sufficient water intake, increase it during the day and reduce it at night to prevent frequent rising and sleep. Usually do not hold the urge to urinate, so as not to damage the bladder, prostate and other organs. Change 7: Stomach shrink into a ball When cold, the stomach muscles and blood vessels will contract, stomach cramps occur, like cramps. If you eat raw, cold, hard food or indigestible large fish and meat at this time, it is easier to burden the stomach. Therefore, the stomach must be well warmed in winter. Wear less short clothes, especially do not wear umbilical cord; eat more warm, easy to digest food, such as hot porridge, hot soup, stew, etc., but meat should not eat more; three meals regularly rationed, so that the stomach can maintain a regular cycle of gastric acid secretion. To remind, although winter hot pot, spicy hot pot, etc. can warm the body, but should not eat more, otherwise it will induce peptic ulcers. Change 8: joint stiffness Cold will lead to muscle contraction, blood flow and synovial fluid secretion is reduced, the tissue around the joints (including muscles, ligaments, etc.) become less compliant, so many people will feel muscle pain, joint stiffness, arthritis pain increased. When the temperature drops suddenly, you must add warm clothes in time and avoid staying outdoors for a long time. Climbing mountains, stairs and other sports will increase the weight on the joints and are not suitable for winter. If you want to exercise, make sure you warm up well so that your stiff limbs do not get injured after being put into strenuous exercise. Diet should pay attention to calcium, vitamins, protein, etc., appropriate to eat more milk, soy products, shrimp, kelp, walnuts, etc. Change 9: depressed mood Some people in winter will appear depressed, no energy, easy to anger and other performance, which is known as “seasonal mood disorder”. The short daylight hours in winter disrupt the secretion of melatonin (a hormone that controls the rhythm of sleep and wakefulness), causing a change in the amount of serotonin that produces a sense of “pleasure”. Cold weather people’s activities, socialization reduced, will also bring depressed mood. In winter, when the sun is good, more sunshine; not too cold, strengthen outdoor exercise, to drive away depression is very helpful. If the lights in your home are changed to warm colors, it will help improve your mood even more.