What constitutes a "HOT" forum topic?

[Crusty Trucker]

I have noticed that some disuussion forum topics have had a bright little "HOT" tag attached to the heading. So far, I have not been able to determine the formula used to apply the label. Sometimes other topic headings will list the same or greater number of responses and will have been listed or entered at the same hour. Does the software system have specific criteria to declare a topic as HOT, or is there some subjectivity entered into the selection?

Not a critical question, but a knowledgeable answer would be appreciated.

[Peter Gariepy]

Its related to the number of readers and the number of responses in a short amount of time.

[Crusty Trucker]

Thank you. I am presuming then that the "system" determines "what's hot and what's not".