many virus's ie; rhinoviruses, rotoviruses etc. are somewhat ubiquitous, so
exposure is usually there, but altering the immune system is the usual way
one catches a cold.  ie; by weakening the immunesystem.

Ms.
Martin, no, that never worked.

http://www.commoncold.org/special1.htm (see myth 3)

http://www.surgerydoor.co.uk/coe/paincentre/fact.shtml (4th myth down)

http://www.chic.org.uk/chicmco/spotlight/downloads/coldandflu.pdf (page 6)

One person's myth is another person's reality ...

A "cold" has been called a "cold" for probably many centuries based
upon the belief that cold weather or cold exposure caused them. This
was before anyone knew anything about viruses. It seemed intuitive, of
course, because of the natural seasonality of many cold viruses, many
being more prevalent in the fall and winter, that coldness causes the
symptoms.

But no one really understands why or how viruses have attained
seasonal patterns. We do know, however, that it isn't as simple as
exposure to cold weather making one more susceptible to a cold virus.

The myth continues, thought, as demonstrated by some of the responses
to your question in this thread, which use a classic form of
fallacious thinking in which one modifies or even invents "facts" in
order to continue supporting a theory that is eroding. In this case,
the theory is that cold weather causes colds. When faced with the fact
that viruses actually cause colds, instead of rejecting then the idea
that the weather does it, some in this thread assert that cold weather
must somehow "weaken" the "immune system", thus making one more
susceptible to colds.

This is similar to the flat earthers from a few centuries ago, when
asked why ships disappear over the horizon, proclaiming that light
waves must bend downwards just a little bit so that, when objects are
viewed from a great distance over the ocean, the light from the boats
hits the water before it reaches your eyes!

PF

< snipped >

When asked for examples of health beliefs that they had acquired during
their upbringing nursing students at a UK university gave these for the
common cold:

Don't go to bed with your hair wet or you will get pneumonia
Keep your feet warm - this stops colds and chills
Feed a cold and starve a fever

Other beliefs not cold related were:

An apple a day keeps the doctor away
Eat crusts on bread - it makes your hair curly
Sitting on a cold surface gives you haemorrhoids
Eating raw jelly makes your nails strong
If you suffer heartburn in pregnancy your baby will have lots of hair
Masturbation makes you blind/mad
Cheese gives you nightmares (avoid at bedtime)
Avoid sexual intercourse during pregnancy - it may damage the baby's head
During pregnancy, boys are carried at the back and girls are carried at the
front
Avoid swimming/sexual intercourse/washing your hair while you are
menstruating
When a person has shingles (herpes zoster), if the lines meet in the middle
they may die
Colicky babies should be given treacle - it settles the stomach
Fresh air for babies strengthens the lungs
Bananas are good for digestion
Bananas and hot mild are very good for insomnia
Drink Guinness when you are pregnant - it is rich in iron
Eating lots of fish makes you intelligent (good brain food)
Garlic thins the blood

Ways to induce labour in pregnancy: drink castor oil; sexual intercourse; an
enema; a hot curry; walk with one foot on the pavement and one foot in the
road; a bumpy car drive.

Source; Holland, K and Hogg, C (20010 Cultural awareness in nursing and
health care. London: Arnold.