I was raised for the first three years of my life in a mountainous region. I have been put to sleep outside on the balcony every day. My mother told me that once my grandmother visited she was panicked to find out I was MIA, to which Mother calmly replied "the snow has made a drift out of the stroller again". What is left from all that is the habit to sleep every night on wide open window (winters usually I am single ... may have some correlation) and the inability to catch cold or flu for more than a day. Getting out of the warm bed on -17 C in the room is unique and highly recommended experience.

So it is perfectly normal in lots of places in the world.