Just to be clear, we're discussing solely the aluminum seal rather than the entire closure, right? Normally I press with my finger to detach that seal. Certain ones include a hinge allowing it to fold back over for coverage. Ensure you avoid the hinged portion when lifting if that's the case. I've encountered zero difficulties detaching these even post-freezing. Should the conversation concern the complete lid assembly including the stopper, that situation differs entirely and merits separate discussion.
I've kept these vials stored away in the freezer since four months back. Caps from other makers usually twist off without trouble but this batch stays stuck no matter what. A shirt and a towel both failed to loosen them.