You'll find that regardless of the school you're at you'll probably be subject to a state-mandated fire drill routine.
For example, the school I was at had the requirement of performing one every month.
You may find that depending where the school is located, you'll have earthquake and tornado drills as well, but they're essentially the same thing.
When the fire alarm goes off, your specific school will have its own expectations of what you should do.
Because these can be different from school to school you'll will want to comprehend fully what they expect from you, and there will be a rulebook that will have this subject covered in detail.
Read it thoroughly.
When it does occur be ready, as the sound blast is very loud and will likely catch a few students and possibly even you by surprise.
You may have trouble thinking straight while it is sounding, especially if the kids are getting out of hand.
Most schools will require that you do the following during a drill: Make sure beforehand that the students know what the correct route is to evacuate.
If your students are older this is not very hard.
If they are younger and if this is their first time experiencing a fire drill they will first need have it explained to them so they can grasp the concept.
This is not the time to panic the children by relaying a story about blazing infernos.
Simply introduce them to fire drills a normal thing that happens in every school.
Let them know they can react to it calmly and orderly.
Teach them that there is more than one way out of the classroom in case one way is blocked by fire or smoke.
They will also need practice if they are really young.
No student left behind.
Make sure you don't leave any kids behind as you make your way out of the classroom.
Do a mental walk-through and remember if any student had left the room for the washroom, to get a drink, or to go to the principal's office.
Take your attendance book with you and take roll.
At this juncture you will likely be expected to jot down a note saying that all of your students are accounted for, put your name on it and send it to the pre-planned area where a member of the administration will gather all of them.
That way your principal will know if any students are unaccounted for.
Keep your class in one place and continue to watch over them.
Just because you are outside does not mean you can let them roam free.
You should be on the lookout for anything and ready to shuffle your kids to a different area that is safe if you need to.
If your pre-designated area for evacuation is compromised you'll want to make sure to keep them away from it.