"Boil lots of water and bring plenty of clean towels." Why?

In movies, impromptu midwifery is something of a dramatic cliché. Luckily, when the baby comes early there’s always someone who knows what to do—an unlikely person, sometimes, such as a cowboy—and he or she instructs a panicky spouse or friend or child to rush off and boil the water and fetch the clean towels.

(I always hope that if this ever happens to me, it’ll be just after I’ve done all the laundry, not just before.)

We never get to see what they do with all that boiling water. Are they going to make coffee for a platoon? How much water does it take to wash a newborn infant?

And how about all those clean towels? Nobody ever comes back and says, “You know what? There’s only one towel in the place, two if you count this dishrag, and neither of them has seen soap or a washboard in a while.” Don’t we always picture a cheery linen closet full of dozens of fluffy white towels, out there in this shack in the desert?

So do these guys always say this because they’ve seen the same movies we have and they know their lines? Or does somebody really have a plan for that vat of boiling water and that acre of fresh linens?

“Boil lots of water and bring plenty of clean towels”—and then what?