What should I record during overnight temperature drop to compare causes safely? The safest answer begins by recording location, trigger and timing before assigning a cause.
What the question is testing
Clear cold nights can drop surface temperatures below indoor-air dew point. The question becomes more useful when it separates what happened first from what was noticed later.
A practical comparison
Record overnight temperature drop, the first affected location and the comparable areas that stayed normal. Repeat the observation only under safe, comparable conditions and note what stayed unchanged.
Limits and next step
Persistent respiratory irritation, combustion concerns, strong chemical odors or visible electrical damage require the appropriate health, safety or building professional rather than continued experimentation. Use the connected atlas guide to build a bounded evidence packet and a clear professional handoff when needed.