Super bad. In hot summer, many people like to take a cold bath to cool off after exercise, but experts suggest that a hot bath is better than a cold bath after exercise in summer, especially when you are sweating all over. Indeed, if you take a cold bath from head to toe after exercise just for quick results, you will feel relaxed at that time, but you may feel weak afterwards, and some even have a headache. This is because when the body sweats a lot, the capillaries are dilated. If you take a cold bath, the blood vessels contract sharply, and the heat in the body is affected by external factors, so it can't be emitted for a while. Moreover, intracranial arteries are rich and sensitive to external stimuli. In the hot season, the head is particularly prone to sweating after exercise. If you wash your hair with cold water, it may cause abnormal intracranial vascular function, leading to dizziness, headache, blackness at the moment and even vomiting. It can be seen that it is dangerous and undesirable to take a cold bath to quickly cool down, especially for people who are not used to taking a cold bath. When their bodies suddenly get cold, they often cause all kinds of discomfort. I suggest that you don't try to feel refreshed for a while, leaving hidden dangers of disease. Experts suggest that for most people who don't usually have the habit of taking a cold bath, it is best to take a hot bath after summer exercise to cool down. Bathing with hot water can wash away sweat, keep hair follicles and skin clean, ventilate the skin, accelerate blood circulation of skin and muscle vessels, dilate capillaries, help the body expel heat, promote metabolism, nourish all parts of the skin, and accelerate the removal of metabolites such as lactic acid. After the blockage on the skin surface and sweat pores is removed, the skin can sweat smoothly, and the smooth "breathing" of the skin is beneficial to the regulation of body temperature. In addition, a hot bath at a proper temperature can soothe the nerves, relax the muscle tissue of the whole body, and even play a certain role in calming, relieving itching, relieving pain and resisting allergy. Although you will sweat more when it is hot in summer, you may feel hotter after taking a hot bath, but you will feel cool and comfortable after a short rest and enjoy that refreshing feeling. Wash your feet with cold water to avoid getting into trouble. The summer heat wave attacks people, and some people who wear light sandals and slippers like to wash their feet with cold water. When they finish washing clothes, they feel much cooler, but doing so often is harmful to their health. Medical research has confirmed that human feet are the farthest branches of blood vessels; The fat layer of feet is thin and the heat preservation is poor; The skin temperature of the sole of the foot is the lowest part of the whole body, which is easy to catch cold. If you often wash your feet with cold water in summer, your feet will get cold further, and then cause a series of complex pathological reactions through vascular conduction, which will eventually lead to various diseases. In addition, because the sweat glands on the soles of the feet are relatively developed, suddenly washing feet with cold water will lead to the sudden closure and blockage of pores, which will lead to the slow perspiration function after a long time. Especially when the sensory nerve endings on the feet are stimulated by cold water, normal vascular tissues contract violently, which will lead to diastolic dysfunction, limb spasm, erythematous limb pain, arthritis, rheumatism and so on for a long time. "Cold War" taboo: going shirtless, it is cold and hot in summer, and many people go shirtless. In fact, in addition to being uncivilized and unsightly, shirtless can't make people feel better. Because the normal body temperature is constant, that is, 37℃. This constancy is achieved through the regulation of nerves and body fluids. Research shows that about 70% of human body temperature is emitted by skin radiation, convection and conduction in the environment of 18℃ ~ 28℃. When the temperature rises to 28℃ ~ 30℃, skin moisture evaporation (sweating) increases, and it increases with the increase of temperature. When the temperature of air or environment is equal to the temperature of human skin, almost all the heat of human body is lost through sweating. If the temperature is higher than the skin temperature, it will absorb heat from the external environment instead of radiating it out. If you go into battle shirtless at this time, the heat absorbed by your skin will increase, and the sweat discharged from your skin will be lost quickly, so you will not be able to dissipate heat through sweat evaporation. Therefore, it will not be cool to go shirtless in hot summer, but it will make people feel more sultry and uncomfortable. In fact, learning to dress appropriately in summer is more conducive to physical comfort. Whether clothes are cool in summer has a lot to do with their hygroscopicity. According to the measurement, when the air temperature is 24℃ and the relative humidity is about 60%, the moisture absorption rate of silk is about 10%, that of cotton is about 8%, and synthetic fiber is the worst, generally less than 3%. So if you want to wear cool clothes in summer, you can wear some silk clothes, cotton cloth made of plant fibers or high-count poplin fabrics. In addition, clothes can be made looser, especially the openings of collars, sleeves and trouser legs, taking into account the functions of "sucking air" and "blowing air" of clothes. Especially for women, flared skirts and dresses can have a greater blowing effect when walking, so they are cooler to wear than suits and skirts. "Cold War" taboo: "Incubate" air conditioners all day long, and the heat is unbearable. Air conditioning has become a magic weapon for many people to escape the heat, but the cool air conditioning environment sometimes just increases the risk of heatstroke. Clinically, long-term dependence on air-conditioned environment will inhibit the internal adjustment and adaptability of human body to external high temperature environment. In midsummer, quite a few people suffer from heatstroke because they fall to the ground after walking on wet or hot streets and leaving air-conditioned places. In order to give full play to the effect of air conditioning, people will close doors and windows when using air conditioning to prevent hot air from invading and cold air from leaking. The ensuing problem is that harmful gases such as carbon dioxide and carbon monoxide in the room are increasing, and the oxygen concentration is obviously decreasing. This environment is conducive to the growth and reproduction of bacteria and viruses. The elderly have insufficient ability to remove germs, and their immunity is relatively low, so they are prone to respiratory infections. Especially for office workers, long-term in air-conditioned rooms will lead to the closure of sweat glands, affecting normal metabolism and secretion; Sitting still and not exercising for a long time will cause unbalanced neck movement and affect the muscles, nerves, spinal cord and blood vessels of the neck. Over time, it will lead to local cervical spondylosis, ranging from stiff neck, stiffness, pain, heavy shoulder and back, weakness of upper limbs and numbness of fingers to abnormal feelings such as headache, dizziness, decreased vision and nausea. Therefore, experts suggest that for people who work in an air-conditioned environment for a long time, one is to change the temperature frequently when using air conditioning. Air conditioning always keeps a constant low temperature, which may reduce the temperature, but it may not have a good heatstroke prevention effect. Medical meteorologists found through experiments that constantly adjusting the room temperature can make people's physiological temperature regulation mechanism constantly in a state of self-protection, so as not to get sick. However, it should be noted that the range of phase transition temperature should be controlled at 3℃-5℃. Secondly, the indoor temperature of air conditioner should not be adjusted too low, with 26℃ as appropriate, and the indoor and outdoor temperature difference should not be too large, with 6℃-8℃ as appropriate. Thirdly, the air conditioner should be equipped with ventilation device, and the window should be opened regularly every morning and evening for ventilation. In addition, when the temperature is not high in the morning and evening, do some outdoor sports appropriately. Such as swimming, walking, walking, etc. , so that sweat glands maintain sufficient sweat secretion ability. Fourth, if the temperature of the central air conditioner in the office building is too low, you should try to wear long-sleeved clothes to avoid bare joints, which can effectively reduce the occurrence of joint diseases. Taboo eating in the cold war: 1 Breakfast is "cold" rather than "hot". A few people are greedy for cold, so they use cold drinks instead of hot soybean milk and milk for breakfast. This practice will not affect the body in a short time, but it will hurt the "stomach gas" in the long run. From the perspective of Chinese medicine, fruit and vegetable juice, iced coffee, iced juice, mung bean paste and iced milk are not suitable for breakfast in summer. Eating "hot food" for breakfast can protect "stomach qi". Stomach qi mentioned in TCM does not simply refer to "stomach", but includes digestion and absorption ability of spleen and stomach, acquired immunity and muscle function. In the morning, all the organs of the body are not out of sleep. If you eat too much cold food at this time, it will cause contracture and blood flow disorder in various systems of the body. Maybe when I first started eating cold food, I didn't feel anything uncomfortable in my stomach, but after a long time, I found that I always seemed to have insufficient food, loose stools, and my skin was getting worse and worse, or there was always phlegm in my throat, which made me feel stuffy and had minor problems. This will hurt the stomach and reduce the body's resistance. Therefore, we should eat hot food such as hot porridge and hot soybean milk first, and then eat vegetables, bread, fruits and snacks. Because milk is easy to produce phlegm and allergies, it is not suitable for people with bad trachea, stomach and skin and people in humid areas. 2. Drinking cold drinks after exercise and strenuous exercise can raise the body temperature to about 39℃. Eating a lot of cold drinks at this time is a strong cold stimulus to the digestive tract, which will cause strong peristalsis of the digestive tract and produce abdominal pain and diarrhea. At the same time, the rapid change of heat and cold will cause the blood vessels in the stomach to contract suddenly, which will cause digestive and absorption dysfunction and lead to indigestion or other diseases. In addition, the throat may be congested after exercise, and excessive cold stimulation will cause sore throat and hoarseness. Therefore, it is not advisable to eat cold drinks immediately after exercise, and it is advisable to take a break before eating. Experts suggest that it is best to quench your thirst with "heat" in summer. Like drinking some hot tea. Because in fact, eating cold drinks can only temporarily lower the temperature and has no effect on quenching thirst. British scientists once chose a particularly hot day to measure the participants with an infrared temperature recorder. The results show that people who eat cold drinks can only reduce the skin temperature around their mouths, while people who drink tea can reduce the skin temperature 1℃~ 2℃ after 9 minutes. Because drinking hot tea can promote sweat glands to relax and sweat, and emit heat in the body, which can completely reduce the temperature of the skin surface. But it is particularly important to note that you can't drink hot and cold drinks alternately. For example, some people just drink cold drinks, and then drink hot coffee, hot milk and so on. Moreover, this change of cold and hot is easy to stimulate their teeth and cause dental diseases. Moreover, alternating cold drinks and hot drinks is not good for the gastrointestinal tract, and it is easy to cause gastrointestinal dysfunction. So drink cold drinks and hot drinks separately, at least 30 minutes apart.