It's both cold, so why do the north and the south have "physical attacks" and "magic attacks"?

Every year after the winter solstice, people always feel a noticeable chill, even biting cold.

Some people say that the cold in the north is like a warrior's "physical attack", direct, fierce, but relatively easy to defend; the cold in the south is more like a magician's continuous magic attack, cold, damp, elusive, and hard to defend against. **They are both freezing,** so why is the real experience so different?

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In fact, this difference includes many factors. If we only talk about temperature, of course, the north is colder than the south. However, in addition to temperature , wind speed and relative humidity are the two most important meteorological conditions that affect the perceived temperature.

In winter, the relative humidity in the south is often above 70%, and even higher on rainy days. In most parts of the north, the wind speed is around level 2 or 3, and the air is relatively dry.

According to the Central Meteorological Observatory's temperature formula, the temperature under different relative humidity and wind conditions at 5°C can be calculated. When the relative humidity in the south is 70%, the temperature will drop from 5°C to 2.6°C, while in the north, a force 7 gale will make the temperature reach 2.5°C.

That is to say, under the same temperature conditions, the south is more susceptible to damp and cold attacks, while the north is less likely to experience biting cold winds. However, the actual temperature in the north is much lower than that in the south in winter. Calculations have found that as long as the temperature difference exceeds 5°C, the effect of relative humidity on the perceived temperature will weaken, and low temperature will become the key to the perceived temperature battle.

On the other hand, the relationship between air humidity and body heat dissipation also affects our perceived temperature. Scientific research shows that when the temperature in a space decreases, the saturated vapor pressure decreases, and the relative humidity increases.

Dry air is a poor conductor of heat. Even if people in the north don't wear much in winter, they can still retain the heat from their bodies to maintain normal body temperature. However, the part exposed to the air feels colder than in the south. The south is generally humid, and the moisture content in the air is much higher than that in the north. The heat conduction rate of humid air is greater than that of dry air, which causes more heat from our bodies to be dissipated into the air and makes us feel abnormally cold.

In addition, the clothes we wear and the quilts we cover are all textiles, which have a certain ability to absorb moisture. Because of the high humidity in the south, clothes are easily damp, and the heat generated by the body will be quickly conducted to the air and dissipated. Even if you cover yourself with more quilts and wear thicker clothes, the effect will be greatly reduced.

Then there is the difference in winter equipment , which also affects our perceived temperature. "You are shivering in the bright sun in the south, but I am in the north where the heating is like spring all year round." Northerners have heating at home, and even the kitchen and bathroom are equipped with radiators. When the heating is sufficient, many northerners walk around in vests and shorts. Southern netizens are more miserable. At most, they can turn on the air conditioner or electric heater in the bedroom. Even so, they have to wear a set of thermal underwear to barely survive the winter. The most uncomfortable thing is that when they want to urinate in bed at night, they can only do it when they can't hold it anymore.

When going out, most northerners are fully armed with earmuffs, masks, scarves, cotton gloves, down jackets, cotton-padded jackets, cotton pants, wool shoes, etc. In a word, it is not a big deal. In the south, most people can survive the winter with just a down jacket and long johns. Although it is a bit cold, people are used to this extreme challenge mode.

Here, I would like to remind the southern little potatoes who are traveling to the north that they must make a good dressing guide before traveling, especially in terms of keeping warm, and remember these four principles:

▲ The inner clothes should not be too thick. Warm, soft and close-fitting materials are the best to reduce air flow. Underwear should cover the waist to prevent the waist and abdomen from getting cold.

▲Mid-layer clothing should have good thermal insulation properties and should not be too tight. Wool, cashmere or pure cotton thermal clothing are good choices.

▲ The jacket should be both cold-proof and windproof . The windproof jacket should not be too loose, and it is best to have a closed design at the collar, cuffs, waist, ankles, etc.

▲Don't forget to keep your head, neck and feet warm. A cold head and neck may cause vasoconstriction and neck muscle spasm, which is not good for blood vessel health. In addition, if the lower limbs are well kept warm, the whole body will feel warm, so you can wear cotton pants and warm thick-soled shoes.

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