Where the requirement actually applies
| State | Transit | Storage |
|---|---|---|
| Lyophilized, sealed | Ambient is generally tolerated | Cool and dark; refrigerated or frozen for long term |
| In solution | Temperature controlled | Refrigerated, limited window |
Why suppliers oversell it
Cold chain sounds like rigor, so it gets advertised as a quality marker even where it changes nothing. A supplier shipping lyophilized material on ice is usually marketing, not protecting. The question worth asking is not whether they ship cold but what their storage conditions are and how long material sits before dispatch.
Where it genuinely matters
Long transit into hot climates, summer ground shipping across multiple days, and anything already in solution. Those are real cases, and they are worth handling properly rather than universally.