As a hypnotist, you must always be on the lookout for potential threats to your subjects.
When entering trance, different people react differently.
I made mention on the instant induction page about people that are called floppers.
Here is a video of an amateur hypnotist finding a flopper...and not being ready for it:
I cannot emphasize enough that you are the one who has to ensure the safety of the people you hypnotize.
Whenever you hypnotize someone you must keep in the forefront of your mind all of the ways that things could possibly become safety issues for your subject, and you must compensate for them.
This is everything from making sure they don't run off, or fall, or that their chair is too close to a platform edge, etc.
Hypnotizing people is fun, but with that fun comes responsibility for their safety.