### fluid | air:

Cool air
* Most cool air holds moisture.
* Some cool air leads to dehydration.
* can hold less moisture than warm air
  - water than warm air
* has more mass per volume than hot air and tends to lift the hot air.
* holds less moisture than hot air
* holds less water than warm air and, consequently there is less water to form precipitation
* is heavier than warm air at the same humidity.
* needs to circulate to keep food safe.
* occupies areas.
* tends to sink, displacing lower warm air and causing vertical mixing.

Dirty air
* Some dirty air is caused by smoke.
* can cause asthma and other bronchial conditions
  - hurt plants, in fact pollution can do deadly damage
* shortens lives, and causes a long list of health problems.

Drier air
* is less likely to condense.
* means warmer air.
* sucks the water out of a tree with greater force.

### fluid | air:

Dry air
* Most dry air leads to daily fluctuations
  - temperature fluctuations
  - passes over membranes
* Some dry air affects breathe patterns
* allows the temperatures to drop much lower overnight than humid air.
* can aggravate upper respiratory problems
  - also cause static electricity and furniture to crack during dry months
* can cause chapping of the skin, increasing the possibility of allergies
  - eye irritation and even respiratory illness
  - problems with spider mites
  - contribute to itchiness, and most homes with central heating are too dry in winter
  - deplete our skin of moisture, causing cracking, chapping, and irritation
  - mean dry skin and dry breathing passages for our pet birds
* causes skin to become dry, as can excessive bathing with strong soaps and hot water.
* consists of nitrogen.
* entering the lungs heats up and is exhaled saturated with moisture.
* exists when all of the contaminants and water vapor have been removed from atmospheric air.
* heats up faster than wet air as it descends the eastern side of the Rocky Mountains.
* increases the evaporation of water from the skin
  - safety margin protecting patients from airborne fungal infections
* is easier to cool than humid air
  - used as the reference in psychrometrics
* leads to wide daily fluctuations
* loses temperature twice as rapidly as damp.
* means dry corks, which eventually come to differ little from sponges.
* poses a threat to plants, and to human throats and noses as well.
* reduces the number of mites.
* retains less heat than moist air.
* tends to cause the plant to put out deformed growth
  - make coughs worse

### fluid | air:

Exhalation
* is also a mode of sacrifice because every time one breathes one is giving to the world.
* is caused by a different mechanism
  - our rib cage shrinking and the diaphragm relaxing
  - either passive or results from constriction of thoracic or abdominal cavities
  - normally a passive process, similar to letting the air out of a balloon
  - part of breathing
  - usually passive as the muscle relaxes
* requires energy.
* usually occurs during the final upsweep and inhalation as the arms start to recover.

### fluid | air | exhalation:

Halitosis
* comes from the lungs.
* defective but valid form of extrasensory perception.
* hereditary problem.
* is an oral health condition characterized by consistently odorous breath
  - unpleasant odor in the breath
* is caused by foods
  - sulfur compounds in the mouth
  - too much sulfur in the mouth
  - volatile sulfur compounds
  - exhalation
  - halitosis
  - the medical term for bad breath
* knows no boundaries when it comes to age, sex, race, or socioeconomic levels.