This is a good subject. Worthy of thought, and good planning. Being a house of multi-cats, thought of fire has been on my mind several different times over the years. I have a couple of avenues in case of fire. One is I have a cat condo on the outside of the bungalow that I live in, that is accessed from the computer room window. This kitty condo is accessible year-round so the cats can go outside and enjoy a bit of fresh air. In the case of an emergency the cats could be put into the condo and the window closed. There are a couple of small doors in the condo outside where a person could retrieve the animals, and put them in a secure location. The 2nd is; I have cages in the house for all the cats. 3 cages are secured to a briefcase carrier with bungee cords. This equipment is In the spare bedroom, and the cages are left open all the time. The cats use the cages periodically as a hideaway so there's no problem putting the cats in the cage if the need arises. The briefcase carrier is like a 2 wheeled cargo hand truck. You would just tip It like a club bag and pull it out on it's wheels. The 2 small cats could go in one of the other carriers, so one trip would get all the cats out.
There are a lot of things to take into consideration. You aren't overly blessed with time, so whatever your planning has to be simple and fast. When you leave the building you'll want all the cats to be going with you at that time, because quite often you don't get a 2nd chance in. The last thing you want to be doing is opening doors or windows to get animals out, and letting fresh air and drafts in to feed the fire.
I know with my 2 options I'd prefer to take the 2nd using the briefcase carrier, rather than opening a window. But the situation at hand will dictate the action to be taken under the circumstances.
Hopefully my plans will spur some thoughts on what to do in case of an emergency. These type of emergencies happen to the other people, maybe we should wear the other people's shoes for time so we can make their plans for them.
Our regional television news program when covering fires house or otherwise normally lists animals lost or injured in fires. It is kind of surprising at the number of fatalities over a year.
You could check with your fire department and see if they have any stickers for your windows that alert the fire department to save your cats if there a fire and you're not home. Or you could made some sign yourself .
As Barkingdog mentioned, I know from talking to volunteer firefighters these window stickers are paid attention to where used. So it might be worthwhile putting some stickers on the windows.