<p>Having a helper or assigning the role of a helper to a more advanced student is a very important safety factor. They can be a victim or provide a watchful eye for any unsafe activities. The lead instructor needs to be able to watch everyone so they can evaluate the overall actions taken. This is necessary for the debrief.
A key safety factor is the "For Real" signal. This can be the standard 3 whistle blasts or something else. At this point, the exercise is over and a real rescue is begun by qualified personnel. Go over this protocol with your students and helpers before starting any scenarios.
I like to work in scenarios throughout my class - keeps them guessing ;-) When a new topic is taught, add a hands on exercise to reinforce. Students love the numerous exercises. If you have lots of helpers, they can stage the incidents while you or another instructor are teaching. This keeps the class moving along.
Make setting safety below part of every scenario - really drill in this concept. When working with ropes, ensure one student is above the accident scene as well.
Don't forget to bring the first aid kit so you are perfectly ready in the unlikely event of an injury.