Cloudscape

Even at moderate cold, most people at some point experience a numbness in the extremities, even when these kept as warm as the rest of the body. This numbness is often enough to severely impair digital coordination, and this being the trump of hominids, it’s unlikely that this is something genetic, as it would otherwise long have been removed through natural selection, considering that the early homo sapiens 30,000 years ago lived in an Ice Age (Palomar College: Early Modern Homo sapiens): by that time they had already spread to what are now temperate regions, such as Europe, and as shown in prehistoric murals, they lived at least partly by hunting with bows and arrows, which requires fine digital coordination. Since it cannot be genetic, it must be the cause of a modification, which we may therefore change.

The extremities suffer from the most heat loss in the body due to the amount of vasculature near the skin, but the amount of heat lost would be equal to the heat provided, were it not that, to conserve heat, the body often decreases heat provisions to the extremities through vasoconstriction, resulting in decreased peripheral temperature, but increased core temperature, ensuring that the vitals remain functional and preventing hypothermia. Yet, unless we are severely exhausted, usually when we suffer from numb extremities, we are actually in no danger of hypothermia, while we might still need those extremities. Such obtuseness from our body could simply not be made possible by evolution, and indeed the obtuseness is actually that of our minds.

Stress often involves noradrenaline, and noradrenaline has been shown to induce vasoconstriction (Bolli P. et al: Adrenaline induces vasoconstriction through post-junctional alpha 2 adrenoceptors and this response is enhanced in patients with essential hypertension.), thus the best thing to do against cold-induced numbness is to relax in spite of it.

Stress is a signal to the body that it is, in some way or other, in need. There are many variants of stress, and based on which it is, it adapts to the need it is signaled to be in. We might distinguish between two main kinds of stress, the stress of deprivation (as of food) and that of danger (as of predators). In the case of deprivation, the body will be more likely to respond with peripheral vasoconstriction to prepare the body’s vitals for deprivation, whereas in the case of danger, it will be more likely to respond with peripheral vasodilation to prepare the body’s skeletal muscles for danger.

Fight mechanism likely involves more dopamine than flight mechanisms, dopamine being involved in motivation, appetite, and aggression, while flight mechanisms likely involve more noradrenaline, which is more involved in hurry, concentration, and vigilance. These individual mechanisms may be seen as responses to the pain of stress, be it that of deprivation or danger. The organism will try to reduce the stress first by trying to fight its cause, and, if that turns out to be impossible, will try to flee from it. In either case, be it deprivation or danger, if we fight (predator, prey, rival), peripheral vasodilation will be more likely. If we flee, vasoconstriction will be more likely. This is why we tend to turn pale from fear, and red from anger.

The body does not distinguish between mental and physical stress, however, because all mental stress, and everything mental, was originally in function of our body and its survival. Nowadays, stress may have nothing to do with anything physical, but our body will still react to it as if it were. In addition, our society causes many situations to be reversed relative to how they were in nature.

For instance, if we are unused to cold, this will cause deprivation stress, a kind of stress that winter may already make us more susceptible to. The signal of deprivation will cause the body to conserve heat, even if we are well-fed and have plenty of spare energy to produce additional heat. Our extremities then undergo vasoconstriction, causing pain in the fingers. This pain may cause additional stress, and since we cannot react to this stress by fighting it, we will be likely to flee from it, causing peripheral vasoconstriction. Pain causes stress, stress causes more pain. It’s a positive feedback mechanism.

It would appear, then, that the best thing to do against cold-induced numbness in the extremities would be to relax, and rather than fleeing from the pain (dissociating from it), fighting it, that is, by actively focussing on the sensation of pain in the extremities.