question: why/how do our noses get congested from cold weather?
comment: There is moisture in your breath. When the air is cold this moisture will turn into water and collect in our nasal passages causing congestion.
passages: Clive Finlayson of the Gibraltar Museum said the large Neanderthal noses were an adaption to the cold, Todd C. Rae of the American Museum of Natural History said primate and arctic animal studies have shown sinus size reduction in areas of extreme cold rather than enlargement in accordance with Allen's rule. Therefore, Todd C. Rae concludes that the design of the large and Neanderthal nose was evolved for the hotter climate of the Middle East and Africa and remained unchanged when they entered Europe 
   Section::::Sense of direction.
  
  The wet nose of dogs is useful for the perception of direction. The sensitive cold receptors in the skin detect the place where the nose is cooled the most and this is the direction a particular smell that the animal just picked up comes from.
  
  Section::::Structure in air-breathing forms.
   During cold, dry seasons, the mucus lining nasal passages tends to dry out, meaning that mucous membranes must work harder, producing more mucus to keep the cavity lined. As a result, the nasal cavity can fill up with mucus. At the same time, when air is exhaled, water vapor in breath condenses as the warm air meets the colder outside temperature near the nostrils. This causes an excess amount of water to build up inside nasal cavities. In these cases, the excess fluid usually spills out externally through the nostrils.
  
  Section::::Respiratory system.:Lower respiratory tract.
   The optimal temperature for rhinovirus replication is 33-35 °C, which corresponds to the temperature of nasal mucosa. At 37 °C virus replication rate falls to 10% to 50% of optimum. This may be the major reason why rhinoviruses can replicate better in the nasal passages and upper tracheobronchial tree than in the lower respiratory tract. Most of the rhinovirus serotypes bind to intercellular adhesion molecule (ICAM), whereas approximately 10% of the serotypes bind to the low-density lipoprotein receptor. Normally, rhinoviruses would infect small clusters of cells in the epithelial layer with little cellular cytotoxicity. Although an increase in polymorphonuclear neutrophils are shown in infected nasal epithelium, little or no mucosal damage occurs from the infection. Nevertheless, rhinovirus infection leads to symptoms of the common cold, which is primarily an upper airway illness. Rhinovirus receptors are insensitive to neuraminidase but are sensitive to proteolytic enzymes.
   Miquel Hernández of the Department of Animal Biology at the University of Barcelona said the "high and narrow nose of Eskimos" and "Neanderthals" is an "adaption to a cold and dry environment", since it contributes to warming and moisturizing the air and the "recovery of heat and moisture from expired air".
  
  Section::::Neoteny.
   These polar stratospheric clouds form during winter, in the extreme cold. Polar winters are dark, consisting of three months without solar radiation (sunlight). The lack of sunlight contributes to a decrease in temperature and the polar vortex traps and chills air. Temperatures hover around or below −80 °C. These low temperatures form cloud particles. There are three types of PSC clouds—nitric acid trihydrate clouds, slowly cooling water-ice clouds, and rapid cooling water-ice (nacreous) clouds—provide surfaces for chemical reactions whose products will, in the spring lead to ozone destruction.
   A rapidly dilating arteriolar circulation to these bones may lead to a sharp increase in the pressure within, in response to acute cooling of the body core. The pain from this pressure is often referred to as "brain freeze", and is frequently associated with the rapid consumption of ice cream. The shallowness of the venous blood supply of the mucosa contributes to the ease with which nosebleed can occur.
  
  Section::::Structure.
   Rhinorrhea is especially common during winter months and certain low temperature seasons. Cold-induced rhinorrhea occurs due to a combination of thermodynamics and the body's natural reactions to cold weather stimuli. One of the purposes of nasal mucus is to warm inhaled air to body temperature as it enters the body. In order for this to happen, the nasal cavities must be constantly coated with liquid mucus. During cold, dry seasons, the mucus lining nasal passages tends to dry out, meaning that mucous membranes must work harder, producing more mucus to keep the cavity lined. As a result, the nasal cavity can fill up with mucus. At the same time, when air is exhaled, water vapor in breath condenses as the warm air meets the colder outside temperature near the nostrils. This causes an excess amount of water to build up inside nasal cavities. In these cases, the excess fluid usually spills out externally through the nostrils.
   Rhinovirus
  
  The rhinovirus (from the Greek "rhis" "nose", "rhinos" "of the nose", and the Latin "vīrus") is the most common viral infectious agent in humans and is the predominant cause of the common cold. Rhinovirus infection proliferates in temperatures of 33–35 °C (91–95 °F), the temperatures found in the nose. Rhinoviruses belong to the genus Enterovirus in the family Picornaviridae.
   Section::::Paleobiology.:Nasal Arch.
   Section::::Polar stratospheric.
  
  Polar stratospheric clouds (PSC's) form in the lowest part of the stratosphere during the winter, at the altitude and during the season that produces the coldest temperatures and therefore the best chances of triggering condensation caused by adiabatic cooling. Moisture is scarce in the stratosphere, so nacreous and non-nacreous cloud at this altitude range is restricted to polar regions in the winter where the air is coldest.
   Reindeer have specialised counter-current vascular heat exchange in their nasal passages. Temperature gradient along the nasal mucosa is under physiological control. Incoming cold air is warmed by body heat before entering the lungs and water is condensed from the expired air and captured before the reindeer's breath is exhaled, then used to moisten dry incoming air and possibly be absorbed into the blood through the mucous membranes. Like moose, caribou have specialised noses featuring nasal turbinate bones that dramatically increase the surface area within the nostrils.
  
  Section::::Physical characteristics.:Hooves.
   Dogs and other canids also possess a very well-developed set of nasal turbinates, an elaborate set of bones and associated soft-tissue structures (including arteries and veins) in the nasal cavities. These turbinates allow for heat exchange between small arteries and veins on their maxilloturbinate surfaces (the surfaces of turbinates positioned on maxilla bone) in a counter-current heat-exchange system. Dogs are capable of prolonged chases, in contrast to the ambush predation of cats, and these complex turbinates play an important role in enabling this (cats only possess a much smaller and less-developed set of nasal turbinates). This same complex turbinate structure helps conserve water in arid environments. The water conservation and thermoregulatory capabilities of these well-developed turbinates in dogs may have been crucial adaptations that allowed dogs (including both domestic dogs and their wild prehistoric ancestors) to survive in the harsh Arctic environment and other cold areas of northern Eurasia and North America, which are both very dry and very cold.
   Nasal hair
  
  Nasal hair or nose hair, or vibrissae, is the hair in the nose. Adult humans have hair in the interior nasal passage. Nasal hair functions include filtering foreign particles from entering the nasal cavity and collecting moisture. In support of the first function, the results of a 2010 study indicated that increased nasal hair density decreases development of asthma in those who have seasonal rhinitis, possibly due to an increased capacity of the faces to filter out pollen and other allergens.
   A cold-stimulus headache is the direct result of the rapid cooling and rewarming of the capillaries in the sinuses leading to periods of vasoconstriction and vasodilation. A similar but painless blood vessel response causes the face to appear "flushed" after being outside on a cold day. In both instances, the low temperature causes the capillaries in the sinuses to constrict and then experience extreme rebound dilation as they warm up again.
   We use our nose and throat as a regenerative heat exchanger when we breathe. The cooler air coming in is warmed, so that it reaches the lungs as warm air. On the way back out, this warmed air deposits much of its heat back onto the sides of the nasal passages, so that these passages are then ready to warm the next batch of air coming in. Some animals, including humans, have curled sheets of bone inside the nose called nasal turbinates to increase the surface area for heat exchange.
  
  Section::::Types of regenerators.:Cryogenics.
   Section::::Cold stratification.
  
  Cold stratification is the process of subjecting seeds to both cold and moist conditions. Seeds of many trees, shrubs and perennials require these conditions before germination will ensue.
  
  Section::::Cold stratification.:In the wild.
   Studies suggest that one biochemical mechanism of low-temperature tolerance is achieved by altering the composition and total content of fatty-acids in their membrane, a phenomenon called homeoviscous adaptation.
  
  Section::::White-nose syndrome.
   Section::::Distribution.
   The conchae comprise most of the mucosal tissue of the nose and are required for functional respiration. They are enriched with airflow pressure and temperature-sensing nerve receptors (linked to the trigeminal nerve route, the fifth cranial nerve), allowing for tremendous erectile capabilities of nasal congestion and decongestion, in response to the weather conditions and changing needs of the body. In addition, the erectile tissue undergoes an often unnoticed cycle of partial congestion and decongestion called the nasal cycle. The flow of blood to the nasal mucosa in particular the venous plexus of the conchae is regulated by the pterygopalatine ganglion and heats or cools the air in the nose.
   In the lungs a temperature of 37 °C and 100% relative humidity (RH) is the ideal condition for the ciliary activity. If the conditions are too warm or cold, the cilia beat slower and at some point not at all. During normal nasal inspiration, air of 22 °C and 40% RH is conditioned into air of 32 °C and 99% RH at the level of the trachea.
   One study into the learning ability of dogs compared to wolves indicated that dogs have a better sense of smell than wolves when locating hidden food, but there has yet been no experimental data to support this view.
  
  The wet nose, or rhinarium, is essential for determining the direction of the air current containing the smell. Cold receptors in the skin are sensitive to the cooling of the skin by evaporation of the moisture by air currents.
  
  Section::::Senses.:Taste.
   There is a nasal valve area in the cavity responsible for providing resistance to the flow of air. This enables an increased time for warming and moistening the air. This area is of two nasal valves. The internal nasal valve is the narrowest part of the airway in the middle third of the cavity. The larger external nasal valve is located in the alar wall.
  
  Section::::Structure.:Internal nose.:Nasal vestibule.
   In vasomotor rhinitis, certain nonspecific stimuli, including changes in environment (temperature, humidity, barometric pressure, or weather), airborne irritants (odors, fumes), dietary factors (spicy food, alcohol), sexual arousal, exercise, and emotional factors trigger rhinitis. There is still much to be learned about this, but it is thought that these non-allergic triggers cause dilation of the blood vessels in the lining of the nose, which results in swelling and drainage.
   Fungal sinusitis
  
  Fungal sinusitis is the inflammation of the lining mucosa of the paranasal sinuses due to fungal infection. It occurs in people with reduced immunity. The maxillary sinus is the most commonly involved. Fungi responsible for fungal sinusitis are "Aspergillus fumigatus" (90%), "Aspergillus flavus", and "Aspergillus niger". Fungal sinusitis occurs most commonly in middle-aged populations. Diabetes mellitus is the most common risk factor involved.
  
  Section::::Types.
  
  The types of fungal sinusitis are based on "invasive" and "non-invasive" as follows:
  
  BULLET::::- Invasive
  
  BULLET::::- Non Invasive
  
  Section::::Signs/symptoms.
  