Reasonable questions that bring up a few points worth considering:
- Gold standard is that infusion sites shouldn't be used for longer than three days due to risk of tissue damage (and subsequent absorption issues) and infection.
- Different insulins have different temperature tolerances, with the fastest (i.e. Apidra etc.) enjoying their speedy action - in part - due to fewer preservatives. Therefore reasonable to assume they're even less tolerant of temperature variations.
- Insulin does not like plastic. Insulin vials are glass because it's largely inert and therefore doesn't contribute to denaturing of enzymes/hormones etc.
I'll often extract insulin from a pod if it fails at activation/startup, but once in use for more than a couple of hours I discard both pod and insulin. Life with T1 is challenging enough so I try and avoid more complication or points of failure than needed.