The vast land of Liaodong is vast like a sea of ice, vast and boundless, you can't see the edge at a glance, the long wind is howling, the snow is flying all over the sky, on the snow field of Linhai, a group of people wearing white cloaks are rowing skis and boards, quietly marching towards Tongliao City.

Although the weather is getting colder and colder, after Xia Xue heard the important news sent by Zhao Quan, she did not hesitate at all, and immediately decided to go to Tongliao City to rescue Dugu Jun, Ouyang Qian was happy and moved, happy that she finally had a message from her sweetheart, and was moved by such a cold day, the queen and the black-clothed guards did not hesitate or fear difficulties, Ouyang Qian of course wanted to fly to Tongliao City hundreds of miles away immediately and rescue Dugu Jun.

"Knowing oneself and knowing one's opponent, one hundred battles will not be defeated", Xia Xue first collected information about Tongliao City through various channels, and mastered the geographical location of Tongliao City, the layout of the city, the facilities in the city, the defenders and other details.

Xia Xue asked everyone to prepare warm clothes and dry food, etc., and personally led a hundred black-clothed guards and more than 200 Khitan warriors carefully selected by Yeluna, Yeluxin, Chaolu, Xiao Da, Tara, Muren, etc., a total of more than 300 people, facing the biting wind and snow, and quietly set off towards Tongliao City.

Due to the heavy wind and snow, the snow on the road is very thick, and it is difficult to walk, and the horseback walking is very slow, and if you walk, it is hundreds of miles, and it is as far away as a snail. Therefore, Xia Xue decided to teach everyone how to make skis and how to ski with them, so that they could glide on the knee-high snow and greatly improve the speed of the march.

With only more than 300 men, the number of combatants was too small, and the city of Tongliao, which was defended by several thousand Turkic soldiers, could only be captured by secret raids. Therefore, you can't set up a tent along the way, and you can't cook on an open fire. If in such a cold weather, if you can't eat hot food and drink hot water, the soldiers will definitely not be able to survive. In this problem, Xia Xue successfully solved the big problem of concealed cooking through the dark and smokeless stove in the wild that her father taught her.

Another big problem: camping in the snow wilderness. If it is not solved well, on such a cold day, it will either frostbite and freeze to death the soldiers; Either the target will be exposed, discovered by the enemy. After thinking about it, Xia Xue decided to use the method that her father had taught her to build a manhole to keep out the cold and camp.

The manhole is a whole underground fortification, which is characterized by good concealment, spacious interior, can dig out any shape and size according to needs, can generally live a few people, or even a dozen people, and can also be equipped with perfect heating, ventilation and lighting facilities. The construction of the ground manhole is generally selected in a relatively open area, with a digging depth of more than 2 meters, which is convenient for personnel to operate and enter and exit, and the upper part is the soil layer, or the roof to be built. Ventilation openings and smoke exhaust pipes can be dug out at the roof of the cave according to actual needs, which is convenient for underground air circulation and fire heating.

The floor is made of frozen soil, which is very sturdy in the cold winter months, and the interior is very spacious. After the interior is kept warm and windproof, the temperature can be kept at about zero degrees Celsius at night. The top is covered with camouflage, which is very hidden, and it is warmer than living in a tent.

The disadvantage of the floor manhole is that it takes a long time to construct and a large amount of work. Xia Xue especially advised everyone to sleep in the manhole at night, especially under the condition of lighting a fire for heating, and must do a good job of ventilation measures to prevent the soldiers from hypoxia or carbon monoxide poisoning.

The plains are like snow, and the north wind rolls up the goose-feather-like snow, which is sprinkled in front of everyone's eyebrows.

The forest is like a high wall, layer upon layer, abounding, not seeing the end, walking through it, making people feel lost in the sense of not distinguishing things, fortunately, Xia Xue has rich experience in survival in the wild, a few days ago when the sky was good, found the location of the North Star, identified the terrain, so as not to go in the wrong direction.

The snow under your feet is white, and from time to time you can see the footprints of animals on the snow, crisscrossing and weaving into a peculiar pattern.

The good weather didn't last long, and in the afternoon it started to snow again, and it got heavier and heavier.

Everyone came to a big river, the river water has been frozen, Xia Xue asked everyone to cross the river as soon as possible. She first walked on the ice of the river, and saw that the river was frozen very strong, so that everyone could cross the river with confidence.

After crossing the river, the sky is getting dark, the distant mountains are black, the dense forests are like ink, and the huge snowfields are like hideous white beasts. The wind suddenly rose, and the snowflakes flickered from all directions like thousands of silver needles, so that they could not open their eyes and their steps were unsteady.

Xia Xue raised her head, only to see a confusion ahead, layers of snow waves whistling and flying in mid-air, the wind howling in the sky, and layers of white fog in the distance, as if there was a huge wind and snow condensing. Suddenly, there was a hint of alarm. "Looks like there's a blizzard coming tonight!"

According to Xia Xue's estimates, the temperature here has dropped to about minus 30 degrees, and it is still daytime, and once it is night, the temperature will only get colder. Even if everyone wore a lot of clothes, it was impossible to hope that they would save their lives on such a cold night.

Xia Xue secretly wondered how to avoid this blizzard, but there was no one in front of her, no one in the back, no one in the back, no one else, where to find a house to hide from the blizzard, helpless for a while.

Xia Xue has experienced countless dangers in her life, so she is not panicked at the moment. The frozen ground is now very deep, and it is as hard as an iron plate, it is impossible to dig a manhole, and a snowstorm is coming, and it is too late.

When she was anxious, she saw the frozen river, and suddenly she remembered the igloo construction method taught by her father, and immediately ordered everyone to go to the frozen place by the frozen river and use a sharp blade to raise ice bricks.

Xia Xue knows that ice is a very convenient building material in severe cold conditions, and ice is a good heat insulator, if the campsite is close to the river, you can easily take ice to build an igloo. The average winter temperature in eastern Liaoning is generally below minus 20 degrees, and the ice on the river can reach nearly 1 meter thick. After taking the ice on the open river, the ice cubes are cut into ice bricks that are half a meter high, half a meter wide and about 1 meter long, so as to facilitate the construction of an igloo.

Xia Xue told everyone that before building an igloo, it is necessary to dig a semi-underground pit according to the size of the igloo, which is not only convenient for concealment but also saves ice bricks. The igloo only leaves one entrance and exit, and the entrance and exit should be leeward, and it is best to turn a right angle and lead to the inside to avoid irrigating wind and enhance warmth. Once the igloo is built, it can be wrapped in hay, etc., and then camouflaged with snow cover. The igloo is a semi-underground fortification, which is very convenient to build when there is enough ice, and it is durable and well concealed, and an igloo usually lives 2-4 people.

In order to demonstrate to everyone, Xia Xue pulled out the dagger tied to the calf of her right leg and got busy on the solid ice all over the ground first.

Xia Xue's dagger is a high-tech product from the future, it is a multi-functional dagger in the field, made of high-tech alloy, extremely sharp, sharpening iron like mud, blowing hair and breaking hair, extremely tough, can hang a ton of heavy objects will not break, with zi bullets can not be penetrated, the blade will never have to be sharpened, and will never roll the blade, gap, anti-corrosion, anti-rust, waterproof, fireproof, the back of the dagger also has sharp serrations, which can be used for logging in the field or cut some hard and strong things, The handle is also equipped with high-tech waterproof and moisture-proof flints, etc., which can quickly make a fire in the wild in any environment and any climate. Using it to slice through these ice cubes at the moment is certainly a piece of cake.

Under everyone's suspicious gaze, Xia Xue cut out many large rectangular ice bricks. Although there is snow here, there are many trees nearby, and there is no shortage of dead grass and dead wood, so the summer snow is made on the spot, and a fire is built to melt the snow. I chose a relatively sheltered place, poured some water, poured ice cubes, poured some water, and then built some ice cubes, the front continued to be built, and the back was constantly frozen, and soon a half-person high frozen overall igloo began to appear.

It was only then that everyone saw the doorway.

Xia Xue also set up the roof, in order to cope with the heavy wind and snow that may come at any time, Xia Xue didn't even leave the door, only left a narrow opening underneath, just enough for a person's body to get into. Xia Xue got in first, laid out the animal skin carpet, and then came out again. Chop firewood and make a small fire in it, and then heat up the house, but Xia Xue reminds everyone that the fire should not be too big and not for a long time, and be careful that the ice in the igloo melts.

Seeing this, everyone was very excited, and they took local materials, cut ice bricks, used ice as "bricks", and used water as "mud" to build an igloo in imitation of summer snow, which was in full swing for a while.

The sky has gradually darkened, the wind is howling in the distance, the ice is a good heat insulator, the igloo is impermeable, can well block the air circulation, the heat in the house can hardly be transmitted through the ice wall to the outside of the house. Therefore, the temperature in the igloo is now about minus 10 degrees, and there is no wind, compared to the outside of minus 40 degrees, it is naturally warm like spring. Everyone wore thick cotton clothes or thick fur coats, and in such an igloo, even if there was no fire, it was completely safe to spend the night.

Everyone had just built the igloo and drilled into it, and suddenly heard a thunder roar outside, and in an instant it seemed that the whole world was angry, the igloo trembled, countless ice ballasts fell on everyone's faces, and the howling wind was like a crazy herd of bison, as if thousands of troops and horses were galloping together, shouting wildly, the heavens and the earth hung upside down, and the whining ghosts cried wolves howled, and through such thick ice, it could also be clearly transmitted to everyone's ears. Just listen to the crackling of the roof, obviously the hurricane has set off countless solid ice and smashed on the igloo, if it weren't for the solid igloo that Xia Xue taught everyone, and it has been frozen with the earth, it may have been blown away together.

The faces of the people turned pale in an instant, and under such a natural power, the manpower seemed so small, and if the people had built the igloo one step later and hid in it, they might have been blown away by this terrible hurricane. Thinking of this, they couldn't help but glance at each other, and sure enough, they all saw a look of fear in each other's eyes, and they stopped talking, sitting in an igloo covered with thick cushions, quietly waiting for the storm to pass.

The wind was howling outside, but the small igloo was warm, and now the temperature here had risen to minus three or four degrees, although it was not as good as the normal climate, but it was much better than outside.

That night, the icy temperature outside dropped to more than minus 50 degrees, and no creature wanted to live in such an environment. But in the small Xiaoice houses, there were bursts of heartfelt laughter.

……

"Hey! Come and help!"

A shout suddenly came from the vast snow, and I saw that a slightly larger snow bag suddenly opened in a snowfield, and a small head stretched out from it, looked around, and then crawled out happily. After Ouyang Qian came out of the igloo, she put on a big white-haired hat, and the white fur wrapped her whole person, looking delicate and petite, holy like a fairy out of the dust.

"Ahh My brother is amazing, what a big wild boar!"

Ouyang Qian saw Ouyang Yong and Zhao Ning, who were wearing thick fur clothes, who were dragging a huge and fat wild boar towards the igloo slowly together, and couldn't help but scream excitedly.

Ouyang Yonghan took off his hat with a smile, scratched the unkempt hair on his head, and shouted again, and saw that several snow bags around him were like flowering steamed buns, opening them one by one, revealing their heads.

"Hey! Come out and help! ”

Everyone agreed, and rushed to take over the wild boar in the hands of Ouyang Yong and Zhao Ning, and everyone plucked the poor wild boar's fur with all their hands, and then happily built a smoke-proof stove according to the method taught by Xia Xue, started a fire, and prepared to cook.

Xia Xue also came out of the igloo to inspect, only to see that the snow outside was clear, the breeze was gentle, the sky was clear, and it was quiet, and last night's snowstorm had already completely buried those igloos, one by one in the snow like a small snow slope, sleek and lovely. I couldn't help but sigh with a long beard, "The blizzard has finally passed, the sky has finally cleared, and the temperature has risen, otherwise I would really be trapped here." ”

After everyone happily ate the wild boar feast, they continued to march towards Tongliao City.

As we walked through the knee-high snow-covered and snow-capped trees, we saw snowflakes and frost pillars hanging from the treetops, which were so pure and white that it was breathtaking. Although it is still terribly cold, the endless forests and snow fields, and the dazzling ice and snow that change endlessly, make everyone dizzy and breathtaking.

After walking for almost a morning, the weather started to deteriorate again. The wind and snow began to attack again, the further you go, the lower the temperature, the cold wind raging, the snow on the ground is waist-high, almost every step has to endure great suffering, if it were not for the skis made by Xia Xue and everyone wearing thick fur and cotton clothes, everyone may not be able to move an inch, and they have already been frozen to death on the road, it is really a difficult journey.

After several days of arduous trekking, we finally arrived at a snow-capped mountain forest more than 30 miles away from Tongliao City. There was silence all around, except for the sound of the soft snow under your feet when you stepped on it. The occasional roar of a tiger or a wild wolf in the distance is terrifying.

After a few days of long-distance running, everyone was exhausted, and Xia Xue asked everyone to go into the mountains and forests to rest, and then wait for the opportunity to attack the city.

The sky gradually darkened, the north wind was howling, cold and cold, piercing into the bone marrow, and the wind rolled up the white snow, whimpering all over the sky, like a mad monster.

The climate is even colder, and everyone is wrapped in thick cotton robes or thick furs, and they have to wear masks to block the wind, so they can barely withstand the wind and snow. "How do you spend the night in this cold mountain forest tonight?" There are no rivers here, there are relatively few ice blocks, you can't build igloos, the ground is frozen as hard as iron plates, and it's impossible to dig holes, what should you do? If there is no place to shelter from the cold and snow, it is estimated that without the enemy to fight, all of your own people will freeze to death here.

Looking at the waist-thick snow and tall trees, Xia Xue suddenly had a flash of inspiration, you can build an igloo with ice, then you can also build an igloo with snow, ice can insulate heat, snow can also insulate heat, the snow here is very thick, and the snow house should also be able to keep warm and avoid the cold.

Xia Xue, who has profound scientific knowledge, understands the principle of the human body feeling cold. I remember my junior high school physics teacher saying, "When your body temperature is dropping, you feel the heat leaving you." "Coldness" doesn't enter your body, and there's no such thing as "coldness". You can think of heat as an object that exists in a certain amount, and the more you lose, the colder it will feel. There are three forms of heat exchange: convection, conduction, and radiation. ”

Xia Xue thought that in the Igloo, three forms of heat exchange are at work: the heat radiated by the people in the Igloo is transferred in the Igloo by convection; The heat is lost by conducting through the snow walls.

However, 95% of the volume of powdered fresh snow is air, which makes it an excellent thermal insulator. Like an insulating layer on an animal, adipose tissues such as blubber can stop heat loss from whales or seals; The animals that are not so fat wrap themselves in air. For example, the otter fur is a thousand times denser than a human hair, and its secret to heat insulation is hidden in its texture, and the otter hair is scaly, so it can trap adiabatic air molecules like snow flakes.

Polar bears, marmots, and even grouse, they dig a snow hole to keep warm. Xia Xue decided to use snow as a material to build an igloo to keep everyone warm.

The shape of the catenary is more evenly distributed than a semicircle, which avoids bulging or bending. Xia Xue knew that this was one of the most stable arches in nature, so Xia Xue decided to build the snow room into the shape of a catenary. The shape of this gradient slope is the same as when people hold one end of the chain in each hand and let it droop naturally, and the weight is more evenly distributed, more stable and stronger.

The interior of the igloo thus built has different curvatures at different heights. The hot air will rise, while the cold air will sink low, away from where you eat, sleep, and relax. In the beginning, the body heat melts away the innermost layer of the snow wall, thus strengthening the barrier between you and your air insulation and the cold outside. Living in an igloo, you are a little stove yourself. Over time, the indoor temperature of the SnowRoom will be about 40 to 60 degrees higher than the outside world, and if you have a companion, the temperature will rise even higher and faster.

After thinking about it, Xia Xue decided to build a few snow houses first to try to see the effect, and she asked Ouyang Qian, Ouyang Yong, Zhao Ning, Zhao Quan, Pan Jiang and others to help.

In the summer snow, the base of the snow cave is enclosed with wooden planks and other objects, and then the enclosed snow is compacted, and then a layer of snow is added and compacted, and so on, until it is 2 meters high. After the snow is piled up, the sapper shovels carried by the army begin to dig holes and repair shapes.

Repaired into the shape of a catenary, enhance stability, the entrance is not large, and the windproof design is made, which can accommodate 2-3 people, after repairing, Xia Xue went in to experience it, and the warmth was really good.

Finally, there was a place to hide from the cold and snow, and everyone was overjoyed when they saw it, and they all praised the queen for being a god, and they imitated and built it, and soon, one after another, snow houses were built one after another. Everyone hid in a warm and quiet room, listening to the sound of the wind howling outside, and for a while it was like a dream, and they were tired and wanted to die, and then fell into a deep sleep.

Seeing that everyone was very tired, Xia Xue did not stop everyone from sleeping and resting, and also seized the time to rest in the snow room.