I imagine anyone coming across this blog (is there anyone out there?) would be more experienced than I am. It's hard not to be, really. However, this advice that I am about to dispense was something that many veteran teachers that I work with could have used if they'd heard it early last week. So, here it goes.
Be prepared for an emergency.
Oh, sure. I'm sure you think you're prepared. You have your box/bin/kit. It probably has a first-aid kit in it, your signal cards/flip book/whatever your district requires. Maybe even a flashlight. Your roster. You might even have emergency contacts for your kids, if you're particularly prepared. You're ready. Heh.
First thing: Make sure everything is working and stocked from the list above. Your first-aid kit needs to be full. Especially of band-aids, wipes, anything that you would need to take care of for your kids in an emergency. This may seem obvious, but think: you run out of band-aids at recess pretty quickly some days. What if you have an emergency the next morning?
Also, that flashlight? Checking the batteries to make sure it works is not sufficient. You need to test it out in the dark. The one my school issued me had working batteries. It didn't give off enough light. I replaced it with this flashlight from IKEA. It's hand-cranked, so you don't have to worry about batteries. It has been field-tested in an emergency (by me an my sprouts) and gives off plenty of light. The crank is also guaranteed to amuse a kid for at least 20 seconds and up to one hour. I already had this on hand, but I'm probably going to invest in some more this weekend. I'm sold on them.
Second thing: Have the kids help you. This was easy in my class because I had already practiced it during our two fire drills. My kids are much more focused and well behaved when they know they have a job and can be appreciated for doing it. I'm not sure I would have put as much thought into it if I had a regular-ed class. With my small group of core (self-contained) students, they each have a job depending on where they are when they line up. First person grabs our emergency cards and will hold them up (hopefully green!) when we are in our place. Second person carries the emergency bin. Third person is caboose and makes sure everyone gets out and to our spot. I have a few things for whatever resource students are with us to do (put a rock in the door so we're not locked out if it's a drill, do our head count, etc.) that I can think of on the spot depending on what type of emergency/drill is going on.
Third thing: This is the one that even the veteran teachers at my school were not prepared for. If you are evacuated, you may be sitting around. For a while. On a bus, outside, in another school's gym, or whatever. The excitement/anxiety/whatever will wear off and your kids (especially primary age or with special needs or both) will be bored. If you are evacuated for an hour (or hours!) you need to have something to do. One of my guys just happened to be working on a notebook full of dry-erase writing activities when we were told to evacuate. He put the pen in his pocket and carried the notebook and eraser out with us without me really noticing until we got outside. I'm really glad I didn't tell him to just put it down, because it really saved us as far as being calm and occupied. My students switched off who was writing and helped each other work on the pages.
There are other things, too. You may need a small snack for your kids, or water, or whatever. This isn't supposed to be all-encompassing. Just think beyond the list your school gave you and think about what your kids would need if out of the school building for more than a half-hour. (Yes, half-hour. Just imagine that, then start extending to hours from there.)
I now have two (small) emergency bins stacked by my door. One just has what we would take out during a planned drill. The one under it will be taken with us any time we have an unplanned incident, in case we are out of our classroom but not dismissed for a while. A set of books on their level, a small anthology of several stories for read aloud, crayons and things to color, what have you. Sitting for hours without something to do during a stressful situation was problematic for a lot of kids (not just my kind of kids!) without something to do.