How can I find the code that's refreshing the page?

How can I find the code that's refreshing the page?

How can I find the specific code that's causing a web page to auto-refresh?
I've looked through the source for an HTML meta-refresh, to no avail. I
also can't find any Javascript "reload" in the main page, leading me to
think it's perhaps externally loaded through a link javascript file.
How would a "pro" track this down, like through Firebug (or other debugger)?
Note:
I'm more interested in the process of being able to debug and track down
something like this, rather than a "catch-all" solution that will stop it
cold (such as disabling the Firefox-wide ability for pages to auto-refresh
themselves).