Confession humor.
I was once in a situation where a "shelter in place" alarm sounded for a chemical release in the area. Stay put, basically. The hazard was not upwind of my location at the start. As the event unfolded I was watching out a window to see changes in wind direction and to monitor movement (should be emergency response only) in the area.
As I watched I realized that structures in the distance were becoming hazy, as if fog was moving in. My concern elevated, adrenaline kicked in, and I began to consider a plan,
When I realized my breath had fogged the window.