Unconventional exercise

Your nose doesnt function so well as a bacteria filter in cold weather. .

Hmm are yo sure? Mine defiantly runs more, surely resulting in trapping more particulate to which bacteria would be attached and potential filtering more bacteria.

Also is just inhaling bacteria enough to causes a lung infection? By this I mean we must all inhale lots of bacteria but we rarely get an infection. Does there have to be an underlying weakness in the lungs or injury? Smokers tend to have more chest infections but I thought that is due to the weakened cilia being less able to clean the lungs? That being the weakness on top of the inhalation of bacteria.

Genuine question, I'm no biology expert.

I've also heard of a minimum temperature, where exercise, causes the body more harm then good.

I know it's a magazine article (so not exactly the best reference) but that appears to be false.

http://www.runnersworld.com/article/0,7120,s6-238-267-269-7442-0,00.html