Comma or fullstop here?

[99bottles]

You don't want to catch a cold. Do you?

You don't want to catch a cold, do you?

Which is correct?

 

[5jj]

The second.

 

[Tarheel]

Either is correct. With the first one there is a longer pause after cold. They mean slightly different things.

Added: Having seen 5jj's post, my first thought was that was my initial response. However, I still think the first one is possible although unlikely.