Because so many iron lungs were needed when the polio epidemics occurred, often there were not enough of them and if you had the kind of polio that you couldn’t breathe and there was no iron lung for you, you would probably die.
When there were not enough iron lungs at Sick Kids Hospital in Toronto, out of desperation some were quickly built in the basement of the hospital. They were not like the normal iron lungs because they were made out of wood. Local business helped supply the materials they used for these make-shift iron lungs. Even a ship building company supplied port holes which were used for the hole for the neck. This is yet another example that supports the old adage that Necessity is the Mother of Invention.