The question of What is the minimum temperature a person can withstand – is the subject of many discussions in scientific circles. Studies show that at temperatures around -30°C without proper protection, the risk of hypothermia increases.
How cold affects people and how it can help humanity.
Some surgeries use induced hypothermia (cooling patients with cardiac arrest; hypothermia is needed to reduce brain damage). At the same time, the body temperature drops to +8 C or to +6 C. The operation lasts up to two hours without consequences for the patient.
In a cryosauna, a naked person can be in vapors of liquid nitrogen for some time. The temperature of which reaches -196 C. And the Eskimos constantly live at sub-zero temperatures and in severe frosts. In their houses made of ice – igloos – the temperature is about 0 C.
Suppose that the air temperature is -70 ° C, but there is no wind. Other weather conditions, such as air humidity, are unknown to us. But let’s take the average value, that is, moderately dry air – 60%.
Anthropometric indicators (height, weight, body volume) and a person’s state of health are also important. Let’s model the situation using the example of an average person (male) 175 cm tall and 90 kg in weight, with a normosthenic body type who has no health problems and bad habits.
What happens when a person finds himself in conditions of abnormally low air temperature?
A little bit of physiology – to supply organs and tissues, there are vessels of various types (muscular and elastic), which are a kind of “pipelines” through which blood delivers oxygen and various nutrients throughout the body.
Blood vessels permeate the entire body and organs, including the skin. A constant body temperature of 36.6°С is necessary for normal functioning. It may vary slightly depending on age and individual characteristics. And for its maintenance, a person needs an air temperature of +18-20 ° C, a sharp decrease of which leads to hypothermia of the body.
What can this cause?
In order to protect the body from hypothermia (hypothermia), reactions are activated aimed at reducing heat transfer by narrowing the lumen of peripheral vessels and reducing sweating. This is one of the mechanisms of thermoregulation.
At the moment of narrowing of the peripheral vessels. The blood flow of the internal organs increases, involuntary chaotic muscle contractions appear – tremors, with the help of which heat is released. There is a release of stress hormones that participate in adaptive reactions in extreme conditions. These processes are compensatory and adaptive. If a person does not find shelter, then the stage of compensation will be ineffective. Then the stage of decompensation develops.
Body temperature decreases. All heat preservation mechanisms are disrupted. Tissue metabolism slows down significantly, which causes a decrease in metabolism. Narrowed vessels expand, which leads to a large loss of heat. Meanwhile, in the central nervous system (CNS), the thermoregulation center is disrupted. Shivering stops, which also causes a drop in body temperature. Brain activity decreases. Such symptoms appear as: disturbance of consciousness; a false sense of comfort, satisfaction; pronounced drowsiness; apathy.
Multiple organ failure occurs (total failure throughout the body), which leads to the death of the body.
Can the consequences be avoided?
Since humans do not have wool. The fingers and toes, the nose and the auricles are devoid of protective fatty tissue. In these places, low temperature affects the fastest, and at -70 °. This process is almost instantaneous.
There are several degrees of frostbite: 1st and 2nd degree. They are considered easy. But if you do not provide the necessary help in time, then, unfortunately. There is a high probability of getting frostbite of the 3rd and 4th degrees.
I would also like to pay attention to what happens to breathing when a person finds himself in such extreme cold. With very sharp cooling of the respiratory organs, and this is possible if you take a quick and deep breath, an instant stoppage of breathing may occur.
But if you inhale such air?
But if you inhale such air slowly and not deeply, then the protective reactions of the body are activated, which help it to adapt and weaken the impact of the damaging environmental factor.
Cold can not only harm, but also help a person. One of the main areas of biophysics is cryonics. Cryonics is a medical movement. It offers the preservation of the human body, embryos or animals at low temperatures before or after the onset of biological death.
According to scientists, preliminary saturation of the patient’s body with a cryoprotectant. And its rapid cooling. Then its preservation at low temperatures is sufficient conditions that open. The possibility for the technologies of the future. It lasts until the complete restoration of the patient’s personality and the radical reconstruction of his body.
If scientific progress maintains the same pace of development. The technologies necessary to return to life may appear already in the middle of this century. Cryopatients can wait 100 or even 200 years – time has stopped for them.