Concur with ExSimGuy; I always count the rows to the nearest exit; I've been through our "cabin procedures trainer" - pax cabin mock-up. Can't see a darned thing when it fills up with smoke.
Which brings me to smoke hoods; we have enough for everybody on our 747F (max 8 people on board incl crew). They provide around 15mins worth of oxygen, so well worth investing in one. Shame pax airlines don't have them;
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rgds Rat