The type of "radiative cold" weather appears with the phenomenon: freezing cold early in the morning, thick fog, but only a few hours later, the sun rises quickly, the air warms up. It sounds pleasant, but for the cardiovascular system, it is a risky endurance test.
When blood vessels are stretched like guitar strings
Early morning is already a "sensitive time" for the body. After a night's sleep, blood becomes thicker, heart rate and blood pressure tend to increase naturally. If you step into a cold environment, the blood vessels under the skin immediately contract to retain heat, causing blood pressure to rise, and the heart to work harder.
The danger lies in the fact that when the sun rises quickly or when the body suddenly comes into contact with a warm environment, blood vessels dilate too quickly. In healthy young people, this adjustment mechanism is still flexible. But in the elderly, people with high blood pressure, cardiovascular disease, diabetes or who are taking diuretics, vasodilators, and poorly elastic blood vessel walls will not "catch up" in time.
As a result, blood pressure can drop suddenly, blood flows to the skin, reduce blood flow to the brain, causing dizziness, fainting, heart rate disorders, even myocardial infarction or stroke.
Professor Walter Willett, a cardiologist and epidemiologist at Harvard T.H. Chan School of Public Health (USA), once warned that short-term but repeated daily temperature fluctuations can trigger cardiovascular events in high-risk groups, especially in the early morning when the physiological blood pressure has already increased.
Radiation cold, pollution and everyday life shocks
Radiation cold" occurs when the sky is cloudy at night, the ground releases heat quickly, making the air layer close to the ground colder than above. This paradoxical phenomenon holds fine dust and pollutants suspended in the lower layer, making the morning cold and toxic to the lungs and heart.
Not only the weather, but even seemingly harmless living habits can become dangerous "boosts": from a warm bedroom to a cold corridor, then to the bathroom and take a hot bath immediately. Sudden temperature changes cause blood vessels to dilate violently, blood pressure drops rapidly, easily causing transient cerebral ischemia.
To prevent stroke, you should not wake up from bed immediately upon waking up. Sit up, do light exercise for a few minutes for your body to adapt. When leaving a warm bedroom, you need to dress warmly enough, avoid drafts.
Elderly people and people with cardiovascular disease should exercise later, waiting for the temperature to stabilize. Limit going out early in the morning on foggy and high-pollution days; if mandatory, wear a fine dust-filtering mask.
Bathing and washing also needs to be careful: the bath water should be at 37 - 40 degrees C, poured from the hands and feet gradually upwards, do not bathe immediately after waking up, after drinking alcohol or eating full. For people with medical history, they should shower in the afternoon, sit and do not lock the bathroom door.
It's a bit of a bit of a bit of a bit of a bit of a bit.
