The expression often relates to someone's physical inability to wake up or respond due to exhaustion.

Physical State

It's used figuratively, not implying an actual count out like in boxing, but rather a state similar to that.

Not Literal

This phrase suggests the person is temporarily unable to engage, not permanently.

Implies an extreme level of fatigue or unwellness, not just being tired or sick.

The person is not available or functional for a period due to their state, but it's not indefinite.

Can carry a sense of empathy or humor, depending on the speaker's tone and context.