Like a cat on hot bricks
Definition 1 of 1
Pro Tip 1/3Visual Imagery
Imagine how a cat would act on hot bricks—jumpy and agitated. This phrase captures a similar human reaction. 
As the clock ticked down, she was like a cat on hot bricks, unable to sit still.
Pro Tip 2/3Intensity of Emotion
This phrase highlights a strong, visible anxiety, not a mild or hidden worry. 
The night before the interview, Jamie was pacing like a cat on hot bricks.
Pro Tip 3/3Temporary State
Use it for situations where the nervousness is temporary, usually tied to a specific event. 
She waited like a cat on hot bricks until her name was called at graduation.