He seemed to be looking at them through the hot air rising from a fire.
This is because not all air can rise at the same time - it's a case of what goes up must come down.
Out on the street it was still early enough for the air rising off the river to be cool.
Cool air rose from below, and she smelled damp earth.
He felt with his fingers, cold air was rising from the slats.
The air was very still and the waning moon not yet risen in the east.
Cold air cannot come down unless hot air rises to take its place.
Hot air rose from the box, but air rich with oxygen.
It isn't really so warm that the heated air should be rising.
If the air is rising faster than the rate of sink, the aircraft will climb.