Why do people freeze to death in summer?

  On May 22, 2021, during the 100-kilometer cross-country race of the Yellow River Stone Forest Mountain Marathon in Gansu Province, a shocking accident occurred: extreme weather was encountered on the mountain, the temperature dropped sharply, hail, freezing rain, and strong wind appeared in some areas. 21 athletes were killed! Moreover, the victims were not “Xiaobai” who knew little about cross-country races, but were China’s top cross-country racers. The number of victims and the severe consequences could be regarded as the highest in the world.
  Tracing back to the reason, the players turned out to be frozen to death! It’s hard to imagine people who sweat as soon as they walk out of the air-conditioned room in the city, how can they freeze to death in the summer?
The occurrence of hypothermia

  In fact, it is not surprising that people freeze to death in the summer, because the ability of humans to maintain their body temperature is not as strong as imagined.
  Compared with other warm-blooded mammals and birds, humans are actually more similar to warm-changing animals: their skin is bare, there is neither thick fur nor feathers covering their entire body. To maintain a constant temperature, humans have to pay a great price: an effective insulation layer must be established on the body surface, and at the same time, the body must continuously produce heat.
  Human beings can keep more heat on the body surface for longer when wearing clothes, but if there is no continuous supplement of energy, these heat can be maintained for a long time. Every gram of fat we eat is completely digested and can produce 9.3 kilocalories, per gram of sugar can produce 4.1 kilocalories, and every gram of protein produces approximately 4 kilocalories. 30% to 50% of these heat is used to maintain body temperature, and it is continuously lost to the body in the form of heat energy. This means that humans must eat and drink frequently to ensure that their body temperature does not change significantly.

The athletes who lost their temperature huddled together tightly

  Maintaining body temperature is so difficult, but “loss of temperature” is very easy. As long as the ambient temperature is lower than body temperature, heat cannot be retained, and cross-country contestants are frozen to death because of this. According to the survivor’s memory, “on a mountain at an altitude of 1,000 meters, a wind of magnitude 7 or 8 carried raindrops and hit the face like bullets. People could not stand or open their eyes. After a long time, I didn’t feel it, and I felt that my tongue was already cold.” At this time, the athletes are suffering from a high-risk hypothermia.
  Hypothermia refers to a phenomenon in which the body’s ability to produce heat and keep warm is less than its ability to dissipate heat for a long time, resulting in a continuous drop in body temperature. The athletes on the mountain are in such a predicament. The temperature on the mountain is low. Many people wear summer clothes. In order to be light and simple, heavy clothes and food supplies are hardly carried on them. The rugged mountain roads are sparsely populated, and external relief and supplies cannot be waited for a long time. Affected by various factors, temperature loss is inevitable.
  It is also difficult for athletes in hypothermia to return to the mountain on their own strength, because even in a state of mild hypothermia, that is, when the body temperature drops to 33℃~35℃, they will have cold limbs, severe chills, severe fatigue, and speech. Symptoms such as unclearness and loss of reason, and at the same time, the muscles are not controlled by consciousness, and people basically lose the ability to move. When the hypothermia is more serious, the body temperature drops below 32°C, and the person is like a “living dead”, entering a state similar to hibernation, muscles no longer spasm, pulse and breathing almost disappear, body surface is cold, and consciousness is lost. If it is severe hypothermia, that is, the patient’s core body temperature drops below 28°C, blood pressure, heart rate, and cardiac output continue to drop, which will eventually lead to cardiopulmonary failure. In this case, only external rescue can save their lives.
Wrong treatment accelerates death

  The symptoms of hypothermia may seem serious, but in fact, even in the state of “living dead”, correct and timely treatment can still save people’s lives.
  In this cross-country race, a group of survivors including athlete Zhang Xiaotao were rescued by a shepherd. The shepherd carried Zhang Xiaotao into the cave, took off his wet clothes, wrapped him in a quilt, and made a fire to keep him warm. Later, the other athletes who were rescued hugged each other to keep warm. After their body temperature gradually recovered, they brought them down the mountain together and were saved. The shepherd’s behavior is the best model for the treatment of hypothermia patients, and the usual first aid methods, including cardiopulmonary compression, rubbing hands and feet, and feeding hot water, will become “death talisman.”
  The “living dead” is actually a state of self-protection. The heartbeat and breathing slow down and maintain basic physiological activities with the lowest energy; the body concentrates warm blood to the core organs to ensure the survival of internal organs; blood circulation in the limbs and body surface It is basically closed, forming an “insulation layer” to retain the remaining heat. At this time, if you blindly press the heart and lungs and rub your hands and feet, it will be counterproductive. Destroying the “insulation layer” will allow the cold blood to continue to flow, resulting in a drop in blood pressure and further lowering your core body temperature. Cold blood flows back to the heart, and at the same time increases the burden on the heart, it is likely to cause serious heart disease, leading to cardiac arrest.

When treating patients with hypothermia, the sides of the neck, armpits, and groin can be rewarmed.

  Feeding hot water also has a great risk. The temperature brought by the hot water is a drop in the bucket, but the side effects caused are great. Hot water can drastically dilate blood vessels, cause hypotension, further lower core body temperature, and may cause rewarming shock. The patient can only be supplemented with sugary warm water after regaining consciousness. In history, there have been tragedies in which the wrong treatment led to the death of hypothermia patients. In order to treat the unconscious teammates, the mountaineers continued to perform artificial respiration and cardiopulmonary resuscitation, and rubbed her palms and feet. As a result, the patient ended up with a bloody nose. The vomiting continued, and eventually he never woke up again.
How to prevent and judge correctly?

  Of course, external treatment is already the last resort. If you don’t want to be “frozen to death” on a hot day, the first thing to do is to prevent hypothermia. When hiking in the mountains, you should raise your awareness of danger, check the weather on the route in advance, find shelter or set up a tent as soon as you know that a storm is coming, and continue your journey when the weather stabilizes; adjust yourself The pace of sweating is reduced, and the evaporation of sweat will take away more heat; wear a windproof and breathable jacket, which is made of fabric with many micropores, and the diameter of each micropore is much smaller than that of a drop of rain. Rain cannot pass through clothing, and it can keep warm in rainy and snowy environments; bring enough food and eat high-calorie carbohydrates at any time; it is best to travel with others and inform relatives and friends of the itinerary and route information in advance; etc. .
  If you fall into a state of hypothermia for various reasons, early judgment of your discomfort symptoms, and timely stop loss before losing consciousness can also increase the survival rate. People can judge whether they are hypothermia by controlling their trembling autonomously. If they can control the muscles to stop shaking, they can be judged as mild hypothermia; if the shaking cannot be stopped under their own control, it is moderate hypothermia.

These equipments are essential for long-distance trail running.

  In addition, as long as there are behavioral and speech abnormalities in a cold environment, such as inability to walk in a straight line like drunk, or difficulty in simple mathematical calculations, etc., you should suspect that you or your teammates have hypothermia, if you have lost yourself Mobility means that it has entered a state of moderate to severe hypothermia. At this point, looking for shelter from the wind, doing a good job of heat preservation, and sending out a distress signal at the same time is the last way to help yourself.
  Human beings are not omnipotent. Human beings are very small in nature. At any time, they must maintain a clear understanding of their abilities, respect nature, and cherish life.