Since August 1st, high temperature and high humidity weather has continued to appear in Tianjin, and it is full of sultry feeling. It can be seen that this year’s "middling" high temperature and high humidity "power" is not small. What effects does hot weather have on health and life? How should the public strengthen health protection? Listen to Yi Xiaoyuan, chief forecaster of Tianjin Meteorological Observatory, and Fan Wenyan, engineer of Tianjin Environmental Meteorological Center, explain the high temperature weather and give advice on how to strengthen health protection.
See how the weather in Tianjin enters "sauna steaming mode"
Since August 1st, there has been a continuous hot and muggy weather in Tianjin. In recent days, the highest temperature in most parts of Tianjin has exceeded 37℃. Coupled with the high humidity, people feel extremely hot and humid, which is also known as "sauna weather".
Sauna weather is not only caused by high temperature, but also by high humidity. Yi Xiaoyuan, chief forecaster of Tianjin Meteorological Observatory, said that wet bulb temperature is a comprehensive measure of temperature and humidity, and it often reflects the sultry weather. Therefore, meteorological departments often use the wet bulb temperature of 25℃ and the temperature of 33℃ as the threshold of "sauna weather".
For example, when the temperature reaches 33℃ and the relative humidity is 55%, the wet bulb temperature will reach 25.5℃, which is the "sauna day" in everyone’s mouth. Sometimes, although the temperature is very high, the relative humidity is not high enough. For example, when the temperature reaches 38℃ but the relative humidity is 30%, the wet bulb temperature is only 23.7℃, and there will be no sultry feeling of "sauna weather" in this weather.
Why does "sauna weather" make people feel hot and humid? Yi Xiaoyuan said that there are two ways to make the human body cool down quickly. One is that the temperature drops. For example, when we enter an air-conditioned room, we will feel cool immediately. The second is to speed up the air flow, for example, we will feel much cooler when we turn on the fan. This is because both the temperature drop and the air flow can make human sweat evaporate, thus taking away the heat in the body, and then we will feel cool. The "sauna weather" is not only high in temperature, but also high in humidity in the air, which makes the sweat on the body surface unable to evaporate, so it will feel very hot.
"Summer solar terms+subtropical high system" perfectly matches "heat"!
It is said that it is the hottest time in Tianjin from late July to early August, because it is in the summer solar term at this time of year, and it is often the hottest time in a year from the climate background. In addition, from the weather system, at this time, the subtropical high will be carried northward to the northern part of China. Subtropical high pressure is a very deep warm high pressure system, and high temperature weather will appear under the influence of this system. In recent days, Tianjin has maintained hot and muggy weather under the control of subtropical high.
According to Yixiaoyuan, during the day on the 4th, the degree of sultry weather in Tianjin remained unabated. It is expected that there will be a weak cold air influence on the night of the 4th, when there may be thunderstorms, and the maximum temperature will drop slightly. However, due to the weak cold air force, the cooling rate is very small. Moreover, the recent rainfall in Tianjin under the control of subtropical high is mostly local heat convection weather. This type of rainfall weather will increase the humidity in the air, resulting in a stronger sultry feeling after rainfall, and will not bring you a refreshing and cool feeling.
Hot weather is closely related to life and health.
Directly affected by hot weather, the most common disease is heatstroke. As an inducing factor, it may aggravate the condition of people who suffer from cardiovascular and cerebrovascular diseases. Fan Wenyan, an engineer of Tianjin Environmental Meteorological Center, said that our common heatstroke refers to the acute diseases caused by the dysfunction of human thermoregulation center and sweat gland failure under high temperature conditions.
Besides the temperature, the factors causing heatstroke are also related to humidity, sunshine, labor intensity, exposure time to high temperature environment, physical strength, nutritional status, water and salt supply and health status. According to the severity of symptoms, it can be divided into mild heatstroke, moderate heatstroke and severe heatstroke, and severe heatstroke is also called heatstroke.
There are various manifestations of heatstroke. The main manifestations of mild heatstroke are palpitation, dizziness, headache, thirst, hyperhidrosis, general fatigue, inattention, uncoordinated movements, and normal or slightly elevated body temperature. The symptoms of moderate heatstroke include nausea, vomiting, cold skin, pale face, obviously increased heart rate, decreased blood pressure or syncope, oliguria, mild dehydration and so on. Severe heatstroke, also known as heatstroke, is a serious fatal disease caused by the imbalance of body regulation function when people are exposed to high temperature and high humidity, and the heat production is greater than heat dissipation, which leads to the rapid rise of the core temperature of the human body and exceeds 40℃, accompanied by skin burning, consciousness disorder and multiple organ dysfunction.
How to protect health in hot weather?
In terms of clothes, you can wear some loose, light and light clothes, which will reflect sunlight and maintain the balance of body temperature. Drink plenty of water, sweat a lot in hot weather, and replenish water in time, so as to "always drink water when you are not thirsty". The elderly and the infirm should avoid activities under the scorching sun, the living environment should be ventilated, sleep should be ensured, digestible food should be eaten, and heatstroke should be avoided as far as possible. Once you feel heatstroke, you should quickly get out of the high temperature and high humidity environment, lie still in a cool and ventilated place, replenish water in time, and remove clothes as much as possible if possible to help dissipate heat. People with severe heatstroke, dyspnea or coma should seek medical treatment immediately and take corresponding first aid measures under the guidance of doctors.
For the elderly, more attention should be paid to health protection in hot weather. To get into the habit of replenishing water, the daily water intake should be about 1500-2000 ml, and the blood viscosity of diabetic patients is higher, so it is necessary to replenish more water. Attention should be paid to avoid foods with high fat, sugar and starch in daily diet, and it is suggested to increase the proportion of coarse grains in the diet appropriately. In summer, you can also eat more ingredients with the functions of dispelling summer heat and benefiting qi, promoting fluid production and quenching thirst. Proper exercise can control weight, reduce the risk of stroke, ensure adequate high-quality sleep every day, and adjust mood to avoid excessive blood pressure fluctuation. Pay attention to the adjustment of air-conditioning temperature, because the temperature difference between indoor and outdoor is too large, it is more likely for the elderly to have blood pressure fluctuations, which may lead to repeated contraction and relaxation of cerebral vessels. In addition, the cerebral vessels of the elderly are prone to atherosclerosis, resulting in poor blood circulation in the brain, which may easily lead to ischemic stroke. Therefore, when the elderly use air conditioning, the room temperature should be controlled at 26℃, and the temperature difference between indoor and outdoor should not exceed 7℃, giving the body time to adapt to the indoor low temperature environment. (Li Dan)