So. When someone you love is on his belly in the 18-inch high attic crawl space? And there is a hole in the chimney that empties into the crawl space? Perhaps it is best not to turn on the forced-air furnace? Because maybe the person you love in the attic will - at the same time you send carbon monoxide laden fumes into said contained space - drop his flashlight and start to feel a little...claustrophobic. OR. Perhaps the person in the attic should let someone know he's in the attic in the first place. BECAUSE HELLO I LOVE YOU.
No apparent brain damage. Just a few tears shed (by me) at the thought of what could have happened.
Here are some illustrated photos of our row house attic. In sum, it's in pretty good shape, but some air sealing is definitely in order.