What Does Cold Weather do to Your Body?

Cold 1936_Pneumonia_prop_strikes_like_a_man_eating_shark

Cold Weather and Lower Temperatures Affect the Human Body

The Human Body is made to deal with the Cold

Cold Temperatures stress the body, but the human body is meant to adapt to colder conditions. You see, low temperatures stress the body; but in a way, it is a very psychological phenomenon. It happens in your mind. The way that you react mentally can have a big effect on how the stress of cold affects you. However, for this article we will discuss primarily the physiological response of the human body to low temperatures.

Over time, the body will adapt to colder conditions. Even brief exposure to low temperatures lead to increased levels of norepinephrine and cortisol, lymphocytosis, decreased lymphoproliferative responses, decreased levels of TH1 cytokines and salivary IgA, and increased lactate levels during exercise. It takes time for the body to de-stress itself in the cold.

Does Exercising Help in the Cold?

Exercising in the cold doesn’t seem to help too much. It can for a short period of time though. Just try not to sweat! Exercising exhausts the bodies energy reserves for immediate heat. Though in general, exercising is a good way to keep the immune system strong. Sweating also causes the body to lose heat quickly.

It seems that previous exposure to cold temperatures is one of the few things that helps the body to adapt. But acute exposure of the skin can have a huge effect on the body’s immune response, so be sure to keep your skin covered in colder temperatures until your body has adapted. They say it takes about 2-3 weeks for your body to adapt to those lower temperatures.

The Cold and the Human Heart’s Health

Cold weather and Cardiovascular Health

People die more often of heart and respiratory diseases in the winter. Vasoconstriction increases blood pressure during the bodies cold-stimulus response. The decrease in cellular plasma also creates a lot more work for your heart.

The Body’s Response to Cold over Time

Exposure to cold causes the sympathetic nervous system to heat the body by constricting blood flow to the extremities and superficial tissue. The body then begins to constrict the flow of the immune system, as well as the nervous system. As the nervous system restricts flow, the extremities lose blood flow until frostbite and more serious, permanent damage occurs.

Who do Mammals Shiver?

Why do you Shiver when it’s Cold Outside?

Over time, the blood pressure increases to cope and the body begins to shiver at a certain point. Once you are shivering heavily, you are at the point where you can get frostbite, or even hurt yourself because the body convulses so strongly. But this can also happen well above frostbite temperatures due to the body’s tolerance level. As people get older, they shiver less, which results in a more rapid drop of temperature upon exposure.

Here’s how Shivering works Neurologically:

Located in the posterior hypothalamus (brain) near the wall of the third ventricle is an area called the primary motor center for shivering. This area is normally inhibited by signals from the heat center in the anterior hypothalamic-preoptic area but is excited by cold signals from the skin and spinal cord. Therefore, this center becomes activated when the body temperature falls even a fraction of a degree below a critical temperature level.

Humans heat themselves Naturally by Burning Fat

Humans also have regulatory neurotransmitters and hormones to help the body burn fat for heat when the body is cold. This is primarily how the newborn and elderly bodies create heat. As we get stronger immune systems, the body shiver response gets stronger, apparently.

Injuries from cold temperatures:

frostbite, hypothermia, heart attacks due to decreased blood flow

References

  1. Human Responses to Cold
  2. Cold exposure and winter mortality from ischaemic heart disease, cerebrovascular disease, respiratory disease, and all causes in warm and cold regions of Europe

  3. The Association of Cold temperature and low humidity with increased occurrence of respiratory tract infections

  4. Exposure to cold and respiratory tract infections [Review Article]

  5. Cold Exposure Human Immune Responses and Intracellular Cytokine Expression
  6. Acute Cooling of the Surface of the Body and the Common Cold
  7. Immune Responses to Exercising in a Cold Environment

  8. Can Exercise Make Us Immune to Disease?
  9. Cross-Talk between the Immune and Endocrine Systems

Common Cold Wiki

No antibiotics, Cough Meds are BS… eat some candy:

Possible explanations may include temperature-induced changes in the respiratory system,[42] decreased immune response,[43] and low humidity causing an increase in viral transmission rates, perhaps due to dry air allowing small viral droplets to disperse farther and stay in the air longer.[44] The apparent seasonality may also be due to social factors, such as people spending more time indoors, near infected people,[42] and specifically children at school.[37][41]

There is some controversy over the role of low body temperature as a risk factor for the common cold; the majority of the evidence suggests that it may result in greater susceptibility to infection.[43] Herd immunity, generated from previous exposure to viruses, plays an important role in limiting viral spread, as seen with younger populations that have greater rates of respiratory infections.[45]

Poor immune function is a risk factor for disease.[45][46] Insufficient sleep and malnutrition have been associated with a greater risk of developing infection following rhinovirus exposure. Due to their effects on immune function.[47][48] Breast feeding decreases the risk of acute otitis media and lower respiratory tract infections among other diseases,[49] and it is recommended that breast feeding be continued when an infant has a cold.[50] In the developed world breast feeding may not be protective against the common cold in and of itself.[51]

The Lymphatic System

The Lymphatic system works in conjunction with the circulatory system to reroute 3 liters of the ~20 processed each day by the body to replace plasma in the blood. Lympha is the Latin word for ‘water’ and refers to the clear liquid that provides autoimmune defense and assists with digestion. The Lymphatic system works alongside the circulatory system to remove waste, toxin, and provide defense for the body from pathogens, infection, and disease.

In order to continue, we have to examine a few of the different fluids in the body:

  • Blood Plasma – the pale yellow liquid in blood, makes up 55% of the bodies total blood, is made up of 95% water, and contains Cellular_Fluid_Contentdissolved proteins, glucose, coagulation factors, electrolytes, hormones, and carbon dioxide
  • Intracellular Fluid –  Cytosol, or intracellular fluid, is the liquid found inside of cells separated into compartmental membranes
  • Extracellular Fluid – fluid outside of cells, mainly blood plasma and interstitial fluid that, in conjunction with intracellular fluid, helps to control movement of electrolytes and water in the body
  • Interstitial Fluid – surrounds the cells of multicellular animals, and is found between the tissue spaces, is very similar to plasma, and pushes water out of capillaries to dispose of waste and continuously reinvigorate the blood stream with water using osmosis and hydrostatic pressure.
  • Transcellular Fluid – the total body water contained within epithelial lined spaces (gastrointestinal, cerebrospinal, peritoneal, and ocular fluids)

We also have to examine the two different parts of the immune system:

  1. the innate immune system – provides immediate defense against infection, found in all plant and animal life. Evolutionarily, this is a much older defense system and is dominant in plants, fungi, insects, and very primitive multicellular organisms. This system activates the adaptive immune system in multicellular organisms
  2. the adaptive immune system –  also known as acquired immunity, this is a subsystem composed of highly specialized, systemic cells and processes that eliminate and/or prevent pathogen growth. This creates immunological memory in response to specific pathogens leading to enhanced responses with subsequent encounters. This is the entire basis of vaccination. Pathogen specific receptors are acquired during the lifetime of the organism. This can be helpful in cases where the body adapts positively, or this can be harmful when autoimmune diseases are acquired. This system is highly adaptable because of somatic hypermutation and somatic recombination (V(D)J recovery) allows for agile re-creation of anti-body cells to fight new pathogens. The antigen receptors are then uniquely expresses on each lymphocyte. This brings us back to where we started….

The Lymph system is therefore extremely involved in the body’s response to pathogens, viruses, and bacteria. Both the innate and adaptive immune systems have humoral and cell mediated immunities (humoral refers to lymph fluid). Remember the two systems, and how blood is contained in a closed system, and lymph is more open. This is a major part of what takes waste out of the bloodstream, and more specifically, how the body fights off infection and eliminates harmful micro-organisms.

So all together, your body is consistently reproducing certain cells to fight off bad guys. and it uses this liquid transport system, which is open around the blood vessels, to do it. This is the final piece of the puzzle, the different types of adaptive immune cells called lymphocytes:

  • Killer T cells – a subgroup of T cells that kills cells infected with a virus or that are damaged or dysfunctional
  • Helper T cells – regulate both innate and adaptive immune responses to help determine the body’s response
  • Gamma Delta T cells – these cells are hard to classify and skirt the border between innate and adaptive cells.
  • B lymphocytes and antibodies – identifies pathogens then (this is where the magic happens, this is from Wikipedia) this antigen/antibody complex is taken up by the B cell and processed by proteolysis into peptides. The B cell then displays these antigenic peptides on its surface MHC class II molecules. This combination of MHC and antigen attracts a matching helper T cell, which releases lymphokines and activates the B cell.[61] As the activated B cell then begins to divide, its offspring (plasma cells) secrete millions of copies of the antibody that recognizes this antigen. These antibodies circulate in blood plasma and lymph, bind to pathogens expressing the antigen and mark them for destruction by complement activation or for uptake and destruction by phagocytes. Antibodies can also neutralize challenges directly, by binding to bacterial toxins or by interfering with the receptors that viruses and bacteria use to infect cells.[62]

So essentially, these specialized cells identity, swarm, and kill pathogens, using the lymph system for circulation and of powerful anti-pathogen cells. This is why the body’s fluid content is so important; it allows the body to regulate and defend itself.

Now let’s talk a bit about the specific organs of the lymphatic system:

  • Lymph vessels – these conduct lymph between the different parts of the body. The lymph vessels transport lymph back to the blood stream replacing the volume lost from the blood during the formation of the interstitial fluid
  • Thymus – The Thymus is extremely important for the immune system, it is where T cells mature, in front of the heart and behind the sternum. It has two lobes that surround the trachea
  • Spleen – an organ found in all vertebrates, this is similar to a very large lymph node to act primarily as a blood filter. It is possible to remove the spleen and maintain life. It recycles iron and stores blood; it also synthesizes antibodies. Its absence will cause predisposition to certain infections. lymph_node_structure
  • lymph nodes – an organized collection of lymph tissue that lymph fluid passes through on its way back to the blood stream.
  • lymph follicle – A lymph follicle is a dense collection of lymphocytes, the number, size and configuration of which change in accordance with the functional state of the lymph node

So you can see that the system works very much in unison with the other bodily systems, mainly the circulatory and gastrointestinal systems to remove wasteful byproducts and toxins involved in consuming food orally. You can feel the concentrations of lymph nodes on the sides of your neck, at the top of the rib cage, and on the soft portion of the elbows and knees.

I think I will post another article on the adaptive immune system, there is just so much here. This should be pretty comprehensive on the lymph system as a whole, but ask any questions and I’ll try to figure it out!