Picking Your Brain...

[Ben Davis]

...would it be possible for he/she to ever contract a cold?

Yes. Direct human contact isn't the only way that viruses spread. I think Esqui, Stimbo and Jacob have covered this off nicely.

What do atheist's tell each other when they sneeze?

I don't know about 'atheists'. I know that some people say 'Bless you' as a result of cultural indoctrination, irrespective of religious beliefs. Others use different cultural references (like 'Gesundheit!'). I don't say a thing: If they covered up, I wait for the sneezer to say 'Excuse me' then I say 'No problem'; if they didn't, I say 'For fuck's sake, stop spreading your germs'.

It was once believed one's soul could escape from sneezing

Not true. This is a clever and recent (~1950's I understand) cover-up by religious apologists looking to escape the real reason: the belief that disease/illness is caused by 'demonic influence/possession'. Since Germ and Disease theories became so well developed and debunked religious claims so thoroughly, apologists decided to take a light-hearted approach to cleaning the egg off their faces. Of course, all they really achieved was to make light of the deaths of millions of people, people who died as a direct result of the 'Demonic' theory of disease.