Is it true babies used to be put in ovens if premature?

Incubator: They are still used for premature babies, to maintain temperature and allow optimal growth and development of baby.

The Armstrong Incbtr: About 35-40 years ago, a common tool for treatment of premature infants was of an Armstrong incubator. The metallic crib had glass windows on all sided and the top. I suppose some thought of it as oven like because it was heated.Oxygen was piped in if needed and vital signs were done by hand. At that point, they either got better or they died. No respirators or monitors were available.