In general media should be stored at the same temperature as the machines environment, and if possible at least 24hours before use.
From Metamark website:
The roll must be at the correct temperature (+10°C to +30°C) before attempting to print, as the heater settings will not compensate for a roll stored in too cold conditions. Often, a roll will need to be used within hours of being delivered in, so be aware that it may still be cold from overnight storage at the courier company. If media is stored in damp conditions, moisture on the film can cause spots in the print, while moisture within the liner will cause it to ripple as it dries out, causing ‘head strike’.