:: Puts on teacher hat:: Stranger danger and Safe Stranger are too great ones. It's great if they know not to talk to to a stranger but they need to do who they can talk to. Police, fire, ambo people etc. How to dail 911 and what info they will be asked. What is a fire danger? How to get out in a fire. These are all things all those ages can handle.
Do mini senarios. Have a child be "hurt" and take care of them so they can see what to expect. Now don't go doing a trauma alert on the younger ones that might be alittle much pending how you do it. I'm a huge one for explaining what a vital sign is and what it tells me. Think meat and potatos hold the salt and butter. Take away the fear of, "Why are you doing this and what is that". You might be shocked at how much they can understand. ( No joke I have a 3 year old that knows if he's coughing alot and he can't breath to ask for his dino mask.... which is his nebulizer. ) With the older kids see if anyone has any conditions you can use. Even if you dont' use them directly. If Billy Bob is allergic to oh bees ( a common thing in Florida) then make a character that is and what you would do to help him if you got called to him after being stung.
Water safety water safety water safety. This seriously can not be mentioned enough. It's summer time these guys are going to pool parties. Going over how to be safe in the water and what do to if someone is drowning would be very good ideas.
Ask parents to take part. Make it an assignment to come up with a fire plan and emergency numbers.
I"m sure if I sat down and really thought about it I could come up with more if not give you a flipping lesson plan. Ok that's my current 2 cents. Off to cook dinner.