I have no idea how long it can live outside the body. But the cold sore virus is a form of the herpes virus. So, it probably can live outside the body for a bit - especially since we are always told how contageous herpes is (including the chicken pox). If your son came into contact with the virus, chances are hes got it, but remember, many people are simply carriers of teh virus, and never break out into coldsores in their lifetime.

Hey,

cold sores are highly contagious; i've read they can live up to 24 hours outside the body.