Storing medication in extreme temperature conditions?

High temperatures (above the storage temperature range listed on the medication) affects its efficacy, it basically cooks them. As I understand it, low temperatures usually do not have this affect, the medicine simply can't temporarily be used because the medication or some parts in it are frozen or no longer properly suspended in the inactive fluid. But I sure as hell would ask the prescribing doctor or the pharmacist if it is true for the medication in your case.