Humans don't naturally survive in scorching deserts without using some kind of post civilization technology to provide a supply of water and relief from heat. Examples: Kuwait City, Kuwait and Death Valley National Park, CA, USA
We don't naturally survive in regions that routinely stay well below freezing for any length of time without using constructed shelters that are sturdy and well insulated and without the expert use of fire - a technology that no other animal has. Example: The Inuit people of the Arctic and the Chukchi people of Eastern Siberia.
Pre-industrial humans never lived in areas that were underwater. Technology has allowed us to pump water from one area to another and build levees to keep the water from returning. Examples: New Orleans, LA, USA and Frisia, Netherlands and Germany.
Humans without civilization cannot possibly live in any kind of concentrations without overwhelming the local food supply. If too many people per acre are present, they begin to starve and the only solution (other than dying in mass numbers) is to import food. For all post civilization cities, this necessarily means modern techniques of mass production and transportation. The larger the city, the more essential this is. Examples: Any city on Earth larger than a few thousand people.
But the more important characterization of our civilization's encroachment into hostile environments is not just our ability to survive there, but as I said, to actually thrive. My main point was that our technology "isolates" us from the negative affects of hostile environments and allows us to live in comfort where our ancestors died in droves and barely scraped by, the result of which is 7 billion humans where a few million existed before.