system
Given the following post, respond as if you're commenting on Reddit:
human
Why does the air above heaters wiggle?

Like above heaters and hot things the air kinda moves? Also why does this only happen with hot things, the air doesn’t do anything noticeable in the cold.
gpt
It happens when an object is significantly warmer than the surrounding air. As the air warms it expands and becomes lighter than the cold air. When it rises up and the cold air falls, this distorts the light passing through causing it to appear wavey.

When an object is colder than the surrounding air, the air close to the object sinks into it creating an insulating layer so there is very little air movement and so no distortion.