Outdoor hypothermia, that is, hypothermia encountered outdoors (hypothermia, also translated as hypothermia, hypothermia), in layman’s terms, it can be said to be a process of freezing to death gradually or suddenly (falling into water). The difference from frostbite is that if you still have the ability to move in the cold field, you may encounter frostbite during the process of moving to a safe place. When losing the ability to move in the cold field, it will suffer from hypothermia, and the worst final result is freezing to death.
Although the amputation caused by frostbite is very tragic, hypothermia (the temperature in the core area of the human body is lower than normal body temperature) can pose a greater threat to human life. And mild hypothermia is easy to ignore, but if not dealt with in time, it can lead to incapacity and even serious consequences. Therefore, keep enough vigilance against hypothermia during outdoor activities in winter. The Xiazi incident in Beiling Mountain on March 10, 2007 was a typical death incident caused by outdoor hypothermia. According to the descriptions of the parties and rescuers, the process of Natsuko from symptoms to death is a typical portrayal of outdoor hypothermia from appearing to worsening. While saddened by the passing of Xia Zi, more people need to understand the dangers and common sense of hypothermia to avoid a recurrence of similar tragedies.
Outdoor hypothermia
Mild Hypothermia. The core temperature is 37~35.55 degrees.
Signs: Uncontrollable shaking, unable to perform complex movements such as ice climbing or skiing, but able to walk and talk. Peripheral vasoconstriction. Among them: at 37~36 degrees, the physical signs are normal, and may start to tremble, and at 36~35 degrees, you will feel cold, the shaking can be light or heavy, and the hands start to feel stiff. Complicated work cannot be done by hand.
Moderate Hypothermia. The core temperature is 35~33.88 degrees.
Signs: Loss of consciousness, loss of motor coordination, especially hands, such as inability to pull zippers. The reason is insufficient blood flow to the periphery. Slurred speech, shaking violently, acting erratically, eg, starting to undress, but not feeling cold. Violent shaking occurs, muscle incoordination becomes apparent, movements are slow and appear strenuous, feet begin to stumbling, confusion begins, and alertness may also appear.
Severe Hypothermia. The core temperature is 33.88~30 degrees.
This temperature will be lethal! At 33.88~32.22 degrees, there will be persistent severe shaking, difficulty speaking, slow thinking and start to forget, obvious decline in mobility, inability to use both hands, frequent trips when walking, emotional depression, depression. Intermittent shaking. Between 32.22 and 30 degrees, exposed skin is bluish-purple and swollen, muscle coordination is very poor, unable to walk, confused thinking, but may also maintain a posture and appear awake. The shaking stops, first shaking violently, then pausing, then continuing the loop. The pause time will gradually increase until the shaking stops completely. Because the heat generated by burning glycogen in the muscles cannot resist the continued decrease in core temperature, the body stops shaking to store glycogen. Falling to the ground, unable to continue walking, curled into a ball to preserve body temperature, muscles gradually stiffened. Due to restricted peripheral blood flow and accumulation of lactic acid and carbon dioxide, the skin turns pale, the pupils dilate, and the pulse rate slows. At around 31 degrees, the human body begins to hibernate, shutting off almost all peripheral blood circulation, and reducing breathing and pulse rates.
Finally, death! At 30 degrees the human body enters a state where it looks like it’s dead, but it’s actually alive! At 30 degrees to 27.77 degrees, muscle stiffness, semi-consciousness, coma, slow pulse and respiratory rate, and possible cardiac fibrillation. Between 27.77 and 25.55 degrees, there is loss of consciousness, heartbeat and breathing are capricious and very shallow, the pulse may not be palpable, and any sudden shock may cause ventricular fibrillation and lead to death. When the temperature reaches 25.55~24 degrees, pulmonary edema, heart and respiratory failure will occur. But it is likely to have died before reaching this temperature.
How to judge whether a person has hypothermia
First of all, we should pay attention to observation at all times. Changes in motor coordination and level of consciousness. If you find that people around you or yourself have such symptoms, you should be alert to hypothermia.
The calmness test method can be used when judging: if the person cannot walk 30 steps in a straight line (similar to seeing if a person has drunk too much, it will be another matter if you drink too much), then it can be judged as hypothermia.
A mild hypothermia can be considered if the shaking stops under control (try to tell yourself: don’t shake, don’t shake, and control the muscle shaking). Do a more complex calculation or reasoning problem (such as counting down from 100, subtracting 9 or 7 each time). If you lose temperature, it will definitely not be counted (note: altitude sickness in high altitude environments can also happen)
If the shaking cannot be stopped under control (try to tell yourself: don??t shake, don??t shake) , but just can’t stop) can be judged as moderate to severe hypothermia!
If you can’t feel a regular pulse, it means that the person’s core temperature is already between 32.22 and 30 degrees. If you don’t save it, you will surely die.
People with severe hypothermia may curl up like a fetus. Try opening his arm, if his arm retracts again, the person is still alive. Dead muscles are immobile
How to help hypothermia patients
Restore body temperature. The basic principle of rescuing a hypothermic patient is to help him maintain his body temperature and at the same time to help them generate heat to restore their body temperature. If a person is shaking, he is capable of rewarming himself at a rate of about 2 degrees Celsius per hour.
1. Rescue methods for mild to moderate hypothermia
(1) First, reduce heat loss. Sheltered areas to reduce heat loss from wind and rain.
(2) Eat and hydrate. Adequate fluid levels and food energy are important for maintaining body temperature and rewarming in hypothermic patients.
The types of food mainly include: carbohydrates, proteins, and fats.
Carbohydrates can produce 5 calories per gram, and are very easy to absorb, can quickly enter the blood circulation, and can produce heat in a short time. It is the best choice in the case of mild hypothermia, mainly including various types of sugars and grains.
Protein produces 5 calories per gram, which is released slowly and can be used as a stable source of calories over an extended period of time. Mainly include all kinds of lean meat, eggs.
Fat can produce 9 calories per gram, which is released more slowly, and digesting fat itself requires a certain amount of energy and water. But the advantage is that the energy can be released slowly over a longer period of time. Mainly including fat, butter and fatty meat.
The principle of feeding people with hypothermia should be the same as starting a bonfire. First, there should be a small fire, then add flammable branches, and after the flame has stabilized, add a large piece of fire. of wood. Namely: immediate supply of energy, short-term supply of energy and long-term supply of energy. According to this principle, it is best to use hot sugary liquids first, then easily digestible sugars or starchy foods. After the patient has improved significantly, add meat and fatty foods. At the same time, pay attention to adding water to avoid digestion Loss of body fluids due to food.
Avoid drinking alcohol to patients with hypothermia, so as not to promote vasodilation and increase heat loss. Avoid caffeine, which can cause dehydration due to its diuretic effect. Avoid nicotine as it can cause vasoconstriction, leading to frostbite.
(3) Increase heat by physical means
Ignition or other external heat sources, use body temperature to help the patient rewarm the body, put the patient in dry clothes, and a normal body temperature. , people in thin, dry clothes get into sleeping bags
together.
2. Rescue methods for patients with severe hypothermia
(1) The first is to reduce heat loss, and thermal insulation measures should be used to completely isolate the patient from the external low temperature. Self-rewarming of the patient from the inside is far more effective than any form of external rewarming, no matter how cold it is. Keep the patient dry, wear sweat-wicking underwear, and keep away from everything that is wet. Use several more sleeping bags, wool blankets, sweaters, moisture-proof pads, etc. to create an insulating layer of at least 4 layers and wrap the patient in it, especially between the patient and the ground. It is necessary to use an aluminum foil survival blanket, which reflects back lost heat and is wind and water resistant.
Note: Never put someone with severe hypothermia in a sleeping bag naked with another person!
(2) Increase body fluids and fuel
Supplement hot sugar water to patients. In people with severe hypothermia, the stomach will no longer digest food, but will absorb water and sugar. Feed thin sugar water every 15 minutes, too thick to absorb. Foods such as energy bars and snickers contain both sugar and protein, which are directly absorbed into the blood circulation, supplying the necessary calories to rewarm the patient.
Urine. People are more likely to urinate in cold conditions. Because blood pressure rises due to vasoconstriction, the kidneys filter excess water from the blood to control blood pressure. A full bladder wastes calories, so urinating should be done. The caregiver will most likely need to help the patient urinate. Open the wrap, then close again, fast and avoid getting wet. Take care to maintain the patient’s fluid levels with hot sugar water.
(3) Physically heated
External heat can be conducted into the main arteries and then to the core. For example: heating the neck, armpits, groin (the base of the thigh) can all heat the arteries nearby. You can use self-heating bags, hot water bottles, hot stones, hand stoves, etc., but pay attention to overheated items that need to be wrapped with dry towels to avoid burns. For patients with severe hypothermia, artificial respiration can increase oxygen intake and promote heat generation.
(4) During the rewarming process, it is necessary to prevent the death caused by the rapid return of the cold blood to the heart!
Inappropriate handling during the rewarming process will actually cause the core temperature to actually decrease and bring fatal danger. The main reason is that peripheral blood vessels (legs, arms) dilate after rewarming, returning cold, stagnant blood to the heart, causing a decrease in core temperature, leading to death. In addition, this blood contains a lot of acetic acid, carbon dioxide, etc., which may cause arrhythmia and cause death. The best way to avoid this is not to rewarm the peripheral limbs and large areas of the body, but only to rewarm the core with hot sugar water, eating, heating the neck, armpits, groin, etc.! Therefore, it is absolutely not allowed to warm hands, feet, etc. for patients with hypothermia. And don’t put people with severe hypothermia in extremely hot environments. For example, it is forbidden to put a person with severe hypothermia in a sleeping bag naked with another person.
(5) Hypothermia and CPR
If a person is severely hypothermic, he may show all the signs of death: cold body, blue-purple skin, fixed dilated pupils , imperceptible pulse and breathing, comatose, unresponsive to stimuli, muscle stiffness…… but he may still be alive, but in a hibernation-like state (as in the case of Weathers mentioned above), this It is still possible to bring them back to life through appropriate means. The job of the rescuer is to rewarm the patient and, if necessary, perform CPR.
In the state of severe hypothermia, the heart is very sensitive and fragile, and external mechanical stimuli (such as CPR, moving, and the return of cold blood from the limbs) may cause arrhythmia and lead to death. Therefore, CPR (mainly cardiac massage) is strictly prohibited in a considerable number of cases.
Before performing CPR, be sure to thoroughly check the patient’s heart rate. It must be remembered that in severely hypothermic patients the heart rate may be as low as 2 to 3 beats per minute, and the breath may be as low as 30 seconds. Cardiac massage while still beating can cause fatal arrhythmias. Therefore, the patient’s carotid artery should be carefully palpated for at least one minute to check for a very slow heartbeat. It should also be remembered that although the heartbeat at this time is extremely slow, its work efficiency (referring to pumping blood) is not low, and the external heart massage is only 20% to 30% of its efficiency. And in a state of inhibited bodily functions (hibernation), it is possible to maintain the body’s need for blood even with only two or three pulses per minute.
Again! Before starting CPR, it must be confirmed that the pulse has completely disappeared! To avoid the death of patients due to cardiac massage!
During rewarming, rescuers should be prepared to continue CPR when the patient does not have a pulse.
Artificial respiration. When the patient stops breathing, gas exchange in the body continues. The body’s oxygen demand becomes very low with the inhibition of bodily functions, and it is possible to sustain life simply by using the oxygen stored in the body. But if breathing stops, then artificial respiration can be started to increase the oxygen supply to the patient. In addition, blowing hot air into the patient’s lungs is also a way to replenish heat. (Xiaojun Pavilion)