"Hotness" is automatically computed based on some combination of votes, number of answers, and velocity -- a new question that quickly gets a bunch of answers and/or votes will score higher. As far as I know, the formula doesn't do any actual content analysis, aside from blacklisting certain words in titles. (The hot list shows up all over the network, so even if a question involving certain language is perfectly reasonable on a language site, health site, etc, SE isn't going to spread it all over the place.)
So, clickbait titles make a difference, especially once a question gets onto the list and then the feedback loop starts (title -> clicks -> higher score -> clicks -> higher score -> ...). It's perfectly fine to write attention-getting titles so long as they don't detract -- the goal of a question title is still, first and foremost, to summarize the question. This is something I expect our community to be good at doing.
I found a really old post documenting the formula, but I think it's been changed a few times since then. Further, there have been recent discussions about what to do with this list because it sometimes attracts controversy. (You can see some of my opinions on this subject there.)