EpiPens (or any AAIs) should be stored:
In a cool, dark place at room temperature, between 15-25°C – DO NOT refrigerate, as temperatures below 15°C may harm the injector device
In an insulated wallet if the person carrying the injector is outside for an extended period of time e.g. hiking
In a safe place where they are easily accessible
People at risk of anaphylaxis follow the advice of their allergy specialist on when to carry an EpiPen.