Cold, because you become pale. Who is most at risk, how to defend yourself even at the table

When we hear the cold tips of hands or nose we are facing the defense mechanism simplest that our body can implement to adapt to the temperature of the environment and avoid freezing. We notice it in these daysi coldest of the yearto understand how freezing temperatures affect our organism. The body works best at 37 C, but, in a state of alert, causes the extremities to cool and thus prepares to protect the so-called “core” and keep the brain, heart, kidneys and lungs functioning. his strategy for preventing hypothermia. The speed of cooling of any object depends on its surface/volume ratio: the more compact the object, the slower it will cool: between an apple and a frankfurter of the same volume, therefore, the latter will cool more. For this reason theand portions of our body
with a high surface area in proportion to the volume of underlying tissue it's more at risk explains Matteo Cerri, neurophysiologist and professor at the University of Bologna, president of the Topical Team Hibernation of the European Space Agency.

Because you become pale

Agricultural and fishing professionals, mountaineers, manual workers, military personnel and the homeless are the most exposed at injuries from cold, but also to
those who practice sports
winter, that feeling of intense cold happened at more areas commonly “hit“: in addition to nose and at fingersit's earsthe toesthe cheeksthe lips and other extremities
exposed or insufficiently coveredlike him eyes. Since these areas are peripheral portions of the body, the brain sends very little blood to them, precisely to prevent it from cooling down – continues the researcher -. Consequentially, these tissues can become distressed until you go, in more serious cases, in necrosis
. The paleness of the skin the consequence of the lack of blood supply to that district. Furthermore, the cold slows down the speed of nerve conduction, “anesthetizing” the peripheral nerves and giving us the sensation of tingling and numbness.

The causes

Exposure to sub-zero temperatures is not the only factor making us say I'm freezing. For example, as Adam Taylor, professor and director of the Clinical Anatomy Learning Center at Lancaster University, reports, if it is windy, temperatures of -20 C can cause frostbite on exposed skin in less than 30 minutes. The tissue freezing the consequence of two joint factors: the temperature environmental below zero (actually the freezing temperature of blood is between -2 and -3 C) elThe body's inability to heat the exposed region because, for example, it no longer sends blood to that district – specifies Cerri -. Exposure to wind increases the rate of cooling. The situation is even worse if we were wet, as the heat is dispersed in the water much more quickly than in the air.

How to defend yourself

If you expose yourself to the coldnecessary provide to the body the adequate energy substrates: calories that can be used quickly by the body to support metabolism and produce heat, such as those provided by carbohydrates. Instead, avoid foods that require long and complex digestion – continues the physiologist -. Moveso as to produce heat through the mechanical action of the muscles. Cover yourself adequately, onion-shaped, because we can move from cold environments to hot environments and vice versa while maintaining our coverage adequate. Like all environmental changes, the body needs some time to adapt: following prolonged exposure to low temperatures, our body will increase its ability to produce heat through tissues such as brown adipose tissue. Once you get home, dry off, drink hot drinks
non-alcoholic, cover the ends well (hands and feet), curl up to reduce heat loss.

Give up alcohol

Avoid substances that can promote vasodilation of the skin vessels e which would make us lose heat as when we take it alcohol. That warming effect, in fact, is illusory – clarifies the expert -. The blood, which is normally at 37 C, flows through the skin and approaches the external environment to which it releases the heat that the body would like to conserve. Furthermore, the alcohol inhibits the production of antidiuretic hormone e promotes diuresis and loss of fluids: this factor can worsen circulation. L'Excess alcohol can depress the activity of the central nervous systemreducing mobility and promoting drowsiness: two conditions that expose the subject to potentially fatal hypothermia.

Who is most at risk

There are pathological conditions that can expose you more to the risk of frostbite, among these heart disease. A impairment of the cardiovascular systemIn fact, it could prevent the heart from pumping the blood necessary to support the metabolism – specifies Cerri –. A thyroid hormone deficiency it can compromise the ability of tissues to activate metabolism and of brown adipose tissue to produce heat. Even the metabolic diseasessuch as diabetes, can undermine the response to cold: on the one hand due to the insufficient action of insulin which no longer facilitates the entry of glucose into the cells that need it, on the other because the peripheral neuropathy that this disease causes can damage skin thermosensitivity, slowing down the activation of the skin's defenses. 'body. The reduced ability to perceive the cold can also increase the vulnerability to frostbite of those who have had a stroke
or has right away peripheral nerve damage.

Because the skin cracks

Finally, who hasn't had any problems in the winter chapped skin and cut lips. It happens because the wind and dry air cause that thin layer of hydration found on the lips, skin and mucous membranes to evaporate, creating cracks and damage, concludes the medical researcher.

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