http://www.nytimes.com/2007/12/05/health/research/05flu.html?ei=5065&en=21ab6eaa062ec6e9&ex=1197522000&partner=MYWAY&pagewanted=print
Dr. Palese bought some guinea pigs and exposed them to the flu virus. Just as the paper suggested, they got the flu and spread it among themselves. So Dr. Palese and his colleagues began their experiments.
By varying air temperature and humidity in the guinea pigs quarters, they discovered that transmission was excellent at 41 degrees. It declined as the temperature rose until, by 86 degrees, the virus was not transmitted at all.
The virus was transmitted best at a low humidity, 20 percent, and not transmitted at all when the humidity reached 80 percent.
The animals also released viruses nearly two days longer at 41 degrees than at a typical room temperature of 68 degrees.
Flu viruses spread through the air, unlike cold viruses, Dr. Palese said, which primarily spread by direct contact when people touch surfaces that had been touched by someone with a cold or shake hands with someone who is infected, for example.
Flu viruses are more stable in cold air, and low humidity also helps the virus particles remain in the air. That is because the viruses float in the air in little respiratory droplets, Dr. Palese said. When the air is humid, those droplets pick up water, grow larger and fall to the ground.
But Dr. Palese does not suggest staying in a greenhouse all winter to avoid the flu. The best strategy, he says, is a flu shot.
He overlooks the obvious. Why go to a greenhouse when we can bring the greenhouse to us?