Temperature excursions can happen at any link in the cold chain: a freezer malfunction at the point of origin, a delayed shipment that outlasts its dry ice supply, a container left on a loading dock, or a clinic freezer that fails after the product arrives. Not every excursion is equally serious; a brief, small deviation is different from an extended one outside the validated range, but both should be documented rather than assumed harmless.
Because the effect of an excursion depends on how far outside range the product went and for how long, a clinic that notices one should not make its own determination about whether the product is still usable. That assessment, and whether the lot should be quarantined or returned, is something to raise with the supplier using the lot number and the specifics of what was observed.
Documenting excursions, including the data from any temperature indicator or monitor included with the shipment, is part of the recordkeeping a clinic should maintain alongside lot traceability records. A pattern of recurring excursions tied to a particular shipping method or carrier is also useful information to raise with a supplier directly.
A documented excursion lets a supplier make an informed call on a specific lot; an undocumented one leaves a clinic guessing about whether a product it already used was ever outside its validated range.