Are you stil contagious after 24 hours of having the flu or cold?

Yes. After having 24 hours of cold or flu symptoms, a person is still quite contagious. It is hard to tell when a person is not contagious, because that varies from case to case, and because the viruses decrease over a few days (they don't all die at exactly one moment in time). The safer thing to do is to avoid spreading viruses by touching others, or by sneezing or coughing on others, for a week.

Related Questions

How long after having the flu are you not contagious?

A few days. People with influenza generallly are no longer contagious after fever and systemic symptoms (muscle aching, headache, etc) are gone. It usually takes 5-7 days after onset of the first symptoms. It may take longer for cough, sniffles, etc to clear up. Read more...