Today's DJ Appellate Zealots column has Sharon Baumgold's How Hot is that Writ? Considerations for Requesting a Stay, which explains:
Two kinds of writ petitions may be deemed "hot."
The first is a petition for writ of mandate or prohibition (an
interlocutory appellate challenge to a trial court order any time before
judgment) that requests a temporary stay during the period of time while the
appellate court reviews the petition, and the temporary stay must issue within
a week or so or it will be too late because something irreversible will have
occurred.
The second is a writ of supersedeas to stay judgment while an
appeal is pending, when the prevailing party threatens to execute on the
judgment contrary to law or take an action that would make reversal on appeal
meaningless.
In both situations, a "hot" writ is one where a stay
is needed very quickly, and it is designed to preserve the status quo so the
appellate court can review the petition or appeal before something irreversible
occurs.