# Cooling event comparison worksheet

Use alongside "Hotter GPUs. Same Coolant Setpoint. What Changed?"
Qualitative investigation aid, not a fault detector or operating procedure.

## Stop and escalate
Record the applicable OEM limits, current alarms, authorized owner and site response procedure first.
Do not delay an operational response to finish this worksheet.
Do not retune controls, move valves or open vents to test a theory without the required procedure and authority.

## Shared context
- Event and affected rack/GPU:
- First observed change and time zone:
- Workload, GPU power and power limit:
- Coolant supply, return and measured branch flow:
- Facility supply and CDU mode:
- Recent work, refill, pump changeover or setting change:
- Sensor locations and measurement boundary:
- Clock alignment and collection/averaging intervals:
- Missing, inferred or questionable measurements:
- Matched healthy comparison and why it is comparable:

## Compare each candidate
Copy this block for: expected workload response; reduced rack flow; reduced heat-rejection capacity; degraded heat-transfer path; sensor or data problem.

- Candidate:
- Supporting evidence:
- Contradictory evidence:
- What remains unknown:
- Next discriminating check:
- Owner:
- Confidence and reason:
- Status: open / supported / weakened / unresolved:
- Escalation trigger:

## Handover
- What was verified:
- What is only an interpretation:
- Next action and authorized owner:
- Evidence files and timestamps:
- Follow-up observation needed to verify the outcome: