Not every window in the old days had a cast-iron radiator in front of it, esp. if a children’s room had two windows in it.
My son, as a child of about 1-2, put a piece of garlic bulb up his nose. Must have thought he was part Italian - we weren’t. Off to the emergency room we went.
Kids can be a vexation.
No acceptable substitute available though...
Window configuration varied, still does, and sometimes bedroom windows were two together, radiator underneath both; other times they were the way you described the to be.
I had a bedroom with the double windows and the third window had an airconditioner in it, so there were many variables and still are.
Small children can and often do rather strange things with object...swallow something they shouldn't even have in their mouth, or, as your son did, when little, stick something strange up a nostril.
I take it that your son is now okay and never did something like that again!