Use 'simmer down' when someone is overly emotional and you want them to calm their feelings.

Emotional Intensity

'Simmer down' is casual and might not be suitable for very formal or serious situations.

Informal Setting

Be careful not to sound condescending when telling someone to 'simmer down'.

Use 'simmer down' to refer to reducing the tensions in an argument or conflict.

Think of 'simmer down' like lowering the heat when cooking — it's about decreasing intensity.

'Simmer down' is often used when addressing a group rather than an individual.