I think everyone would agree it's, basically, a 'last ditch' operation. And I think this is one area where a shrouded or hammerless revolver has a distinct advantage over a semi-auto.
There's also a great selection of FRC's (Fire Resistant Clothing) available today, so if budget allows you might want to pick up a jacket or two.
I've never really seen any FRC trench coats, but they MAY be other there. Usually, they're more of the bomber or baseball jacket type design. And they're only marginally more expensive than the equivalent non-FRC type.
Hey, and listen. If anyone feels they would need a specific item for such carry, like a FRC trench coat, feel free to PM me. Know some folks in the business, and maybe you could get it custom made AND at a reasonable price. I'd sure be willing to look in to the matter, if it would benefit someone.